Spring training has arrived. Spring camps across Arizona and Florida opened last week, and, later this week, Cactus League and Grapefruit League play will begin. Real live baseball is right around the corner. Yeah, it's meaningless baseball, but spring training games are fun in their own way.

All 30 clubs have a plethora of storylines to follow this spring. At least one of those storylines is, inevitably, an individual player with something to prove. A youngster who wants a big league job or a veteran looking to show everyone he still has something in the tank. Guys like that. Spring performance is not very predictive but, for these players, it's not meaningless either.

With exhibition games about to begin, here is the player with the most to prove during spring training play these next few weeks. Roster sports are on the line and, in some cases, so are careers.

Most interesting non-roster invitees for spring training 2019

OF Steven Souza Jr. A series of pectoral strains limited Souza to 77 games and a .220/.309/.369 batting line with five home runs last season. That's after coming over in a seven-player, three-team trade and hitting .239/.351/.459 with 30 homers for the Rays in 2017. Souza turns 30 in April and is under team control through 2020. The Diamondbacks never saw the good version of him last year and you can be sure they want to see him this year, including in spring training.

SS Dansby Swanson. One one hand, Swanson turned only 25 earlier this month and he's a former No. 1 overall pick. On the other hand, Swanson is a career .243/.314/.369 hitter in parts of three seasons, and he's looked more like a complementary piece than a potential cornerstone. It's not put up or shut up time but it's getting close. Braves GM Alex Anthopoulos has never been shy about trading young players. With Johan Camargo available to play short, Swanson figures to have to do something soon to prove he's worth keeping around, and that begins in spring training.

1B Chris Davis. Is there any hope for Davis at this point? At age 32 is he suddenly a true talent .168/.243/.296 hitter like we saw last year? Davis told reporters, including MLB.com's Joe Trezza, that he spent the winter working with sports psychologists and digging into analytics in an effort to get better. He is owed $92 million over the next four years and that almost certainly means his job is safe for the foreseeable future. That said, teams are increasingly willing to eat big money contracts and release an unproductive player. Davis is going to have show some signs of life -- any signs of life, really -- and soon to stave off a similar fate with the Orioles.

2B Dustin Pedroia. Knee surgery and subsequent complications limited Pedroia to three games last season and 105 games in 2017. A few days ago he told reporters, including Justin Leger of NBC Sports Boston, that he "wouldn't have done" the surgery had he known what he knows now. Pedroia has had one fully healthy above-average season since 2013 (2016) and this spring he has to show he can be productive not only after the knee problems, but at age 35 and with his 36th birthday a few months away. He's been proving doubters wrong his entire career and I wouldn't bet against him. Clearly though, this is an important spring for Pedroia and the Red Sox

SP Yu Darvish. There's no way to sugarcoat it: Darvish's first season with the Cubs was a disaster. Year one of his six-year, $126 million contract featured a 4.95 ERA in eight starts and season-ending elbow surgery. Darvish is healthy now and he's still unbelievably talented. It shouldn't shock anyone if he comes out and has an ace-caliber season in 2019. That said, Darvish is closing in on his 33rd birthday and the mounting arm injuries are a concern. A good spring training wouldn't exactly mean all is forgiven in Wrigleyville, but it would be a step in that direction. 

SP Lucas Giolito. No shortage of White Sox players who need a good spring, huh? I could've easily gone with Yoan Moncada or Tim Anderson here. Instead, Giolito gets the pick after leading the league in walks (90) and earned runs allowed (118) last season. The former No. 1 pitching prospect in baseball had a 6.13 ERA in 32 starts -- give him credit for making 32 starts, not many pitchers do that these days -- and he seemed to try everything throughout the season. More fastballs, more curveballs, you name it. It never really came together. Top pitching prospect Michael Kopech will miss the season with Tommy John surgery. Adding another disaster season for Giolito on top of Kopech's injury would dim the lights on the rebuild considerably. I feel like he needs a good spring for himself more than anything, just to build some confidence.

SP Sonny Gray. Give the Reds credit. It would've been easy to do little to nothing this offseason and plow forward with the rebuild. Instead, after four straight 94-plus loss seasons, Cincinnati made moves to get better. That makes them an outlier these days. They traded for several impending free agent veterans (Matt Kemp, Yasiel Puig, Tanner Roark, Alex Wood) but only one of them, Gray, was given a contract extension. The Reds traded a prospect and a draft pick to get Gray, then immediately handed him a three-year, $30.5 million extension. That's after a 4.90 ERA last season. Cincinnati is betting on a rebound and Sonny having a good spring training would be a welcome sight.

OF Tyler Naquin. Three years ago Naquin finished third in the AL Rookie of the Year voting. Injuries and ineffectiveness limited him to 80 big league games from 2017-18, during which he hit .256/.287/.341 with three home runs and eight walks. Naquin turns only 28 in April, so he's still in what should be his peak years. The Indians outfield is the land of opportunity right now. A good spring training would go a long way to landing Naquin a starting job in 2019. Few players in baseball have as much to gain with a strong spring this year.

SP Jon Gray. Despite little to no rumors, I have to think the Rockies fielded many trade calls about Gray over the winter. He's only 27, he's under control through 2021, and as recently as 2017 he posted a stellar 3.67 ERA (38 percent than league average after adjusting for Coors Field) with strong strikeout and walk rates. Teams are always trying to buy-low on talented players coming off a down season. Colorado wisely hung on to him because he has ace potential and they've seen it at times in recent years. Gray looking like the Jon Gray we saw from 2016-17 this spring would be a potentially huge development for the Rockies.

SP Daniel Norris. Groin trouble and a 5.42 ERA in 146 innings from 2017-18 have Norris on the outside of the Tigers rotation looking in at the moment. He is still only 25, however, and lefties who have a history of missing bats then to keep getting chances, especially when they play for rebuilding teams. It is entirely possible there is nothing Norris can do this spring to win a rotation spot. At the very least, he wants to make it difficult for the Tigers to send him to the bullpen or Triple-A.

SS Carlos Correa. Let me preface this by saying I think the Astros shortstop will have a great season and be on the short list of AL MVP candidates come the end of September. That said, Correa was so clearly hampered by a back injury for much of last season. He hit .180/.261/.256 in 37 games after returning from the disabled list in August and .239/.323/.405 in 110 games overall. There's no way a healthy Correa hits .239/.323/.405 across a full season, right? Right. A healthy and productive spring would go a long way to easing concerns about his back going forward.

OF Jorge Soler. I feel like we've reached make or break time with Soler. He turns 27 later this month, he is three years from free agency, and he will make a not insignificant amount of money the next two years ($4.67 million annually from 2019-20). We've been hearing about him for several years and we're still waiting for that big breakout year. To be fair, Soler looked to be in the middle of that breakout year (.265/.354/.466) before a foot injury ended his season in June. The Royals are in the "accumulate talent" phase of their rebuild. Soler becoming a centerpiece player would move the rebuild forward quite a bit. Last year's breakout continuing this spring would be welcome news.

SP Matt Harvey. Harvey is already talking the talk this spring. "I wouldn't say I'm happy for the experiences I've gone through, but I think for the rest of my career it'll better me as a teammate and a player," he said to reporters, including ESPN's Pedro Gomez, when he reported to Angels camp last week. Harvey was good but not great with the Reds last year and, at age 29, he's still young enough to command a nice multi-year contract as a free agent next winter. He has to be healthy and productive for that to happen, and eliminate the headaches as well, and that's a process that begins in spring training.

C Austin Barnes. Two years ago Barnes hit .289/.408/.486 with great framing numbers, and he usurped Yasmani Grandal as the Dodgers starting catcher in the postseason. He followed that with a .205/.329/.290 batting line last year. Grandal departed as a free agent and Los Angeles imported late-career Russell Martin as their catching safety net. With two top catching prospects coming in Will Smith and Keibert Ruiz, this may be the last time Barnes enters spring training assured of a big league roster spot. I don't think that's hyperbole.

C Jorge Alfaro. Alfaro was the second piece behind pitching prospect Sixto Sanchez in the J.T. Realmuto trade, and he's a good young big league catcher. He hit .262/.324/.407 with 10 home runs last year, his arm is maybe the strongest in baseball, and the framing metrics love him. A 25-year-old who can do what Alfaro does is a nice little piece. It's probably unfair to say he has something to prove with the Marlins this spring. More than anything, he has an opportunity to show folks that hey, I can play too.

RHP Jimmy Nelson. The Brewers have a few pitchers with something to prove this spring. Chase Anderson led the league in home runs allowed last year. Zach Davies battled injuries all year. Nelson, though, has not pitched since September 2017 due to shoulder surgery. He pitched like a low-level ace before the injury, an injury that occurred while running the bases because the National League needlessly requires pitchers to hit, but I digress. Nelson is healthy and expected to have a full and normal spring training, though of course the Brewers won't push him too hard. Milwaukee had the best record in the league last year and they improved quite a bit over the winter. Seeing Nelson healthy and throwing well would give the club another reason to feel really good about the 2019 season.

OF Byron Buxton. I could've easily gone with Miguel Sano here, but, in Buxton's case, the Twins have two other very good outfielders (Eddie Rosario and Max Kepler) with a top outfield prospect (Alex Kirilloff) coming. Moving Sano to DH to replace Nelson Cruz in 2020 feels like an inevitability. Another disappointing and/or injury-riddled season for Buxton could end his time in the organization. He is so very clearly talented but we're all still waiting for that consistent and fully healthy breakout season. At age 25, it's time to do it.

2B/OF Jeff McNeil. McNeil came up last year and hit .329/.381/.471 with only 24 strikeouts in 63 games. His reward? The Mets trading for the highest-paid player at his position (Robinson Cano) and adding another veteran free agent at the position (Jed Lowrie) for good measure. McNeil, a late bloomer who will turn 27 in April, is now moving to the outfield and you can be sure he's looking forward to showing everyone he can do it. A player who's had to scratch and claw to get to where he is right now will embrace the challenge. It's the perfect "something to prove in spring" scenario.

1B Greg Bird. Give the Yankees a truth serum and I think they'd tell you they want Bird to have a monster spring and wrestle the first base job away from Luke Voit, who was a monster (.333/.405/.689) after coming over the trade deadline last year. The Yankees love Bird and believe he has considerable upside as a high on-base/big power lefty bat, which is the one thing their lineup lacks right now. Bird has battled injuries and ineffectiveness the last three seasons. If we see more of the same this spring and this season in general, the Yankees might turn the page completely.

OF Nick Martini. As a 28-year-old rookie last year Martini hit .296/.397/.414 in 55 games and batted leadoff in the Wild Card Game. The recent Robbie Grossman signing combined with Jurickson Profar's (and Chad Pinder's) versatility means Martini reported to spring training last week having to compete for a big league roster spot. When you're an older rookie who has experienced only small sample size big league success, you're going to have to battle to stick around. This spring Martini has to show last year was no fluke.

OF Odubel Herrera. Stagnating third baseman Maikel Franco is an easy target for an exercise like this. To me, Herrera is at a more critical juncture for the Phillies because his OPS+ has gone from 111 to 109 to 103 to 94 in his four years as a big leaguer, and his defensive WAR has gone from 1.4 to 0.9 to 0.7 to minus-1.0. There's also four years and $25.5 million remaining on his contract. That's kind of a big deal. The Phillies had a very active offseason but is it enough to make them favorites in the NL East? Not clearly, no. Herrera going back to the 2015-16 version of himself could change the balance of power in the division. He has to show he belongs in the lineup everyday this spring.

1B Josh Bell. Where'd the power go last year? Bell smacked 26 homers in 159 games in 2017 en route to a third-place finish in the NL Rookie of the Year voting. Last year he dropped down to 12 homers in 148 games. That's ... alarming. Everything else was good though. The average held steady, walks were up, strikeouts were down. It's just that when your slugging first baseman stops slugging, you can't help but wonder what's up. Bell can ease concerns about his vanishing power with a big spring training for the Pirates.

1B Eric Hosmer. Hosmer is a very divisive player and 2018 goes to his detractors. He hit .253/.322/.398 with 18 home runs in year one of his eight-year, $144 million contract. Ouch. Last year was Hosmer's seventh full season and his fourth with no better than a 102 OPS+ or 1.5 WAR. That is not a $144 million player. That said, Hosmer is only 29, and he's a year removed from a .318/.385/.498 batting line and 25 homers. Seeing that version of Hosmer in spring training would make the Padres feel a bit better about their investment, at least temporarily.

3B Evan Longoria. Several different Giants would fit here. Jeff Samardzija, Mark Melancon, Brandon Crawford, Joe Panik, so on and so forth. Longoria gets the nod because he hit .244/.281/.413 last year -- yes, he had a .281 on-base percentage -- and still has four years and more than $62 remaining on his contract (minus what the Rays are paying him). Ouch. At age 33, expecting to see peak Longoria again is foolish. Can he at least get his on-base percentage back above .300 though? If not, we might be talking about Longoria as an early release candidate given the way teams are eating money to unload their mistakes these days. 

OF Domingo Santana. I imagine there is nothing the Mariners would love to see more than peak Felix Hernandez this spring. With his 33rd birthday coming up and all those innings on his arm, that is very unlikely to happen. Bummer. The 26-year-old Santana came over from the Brewers this winter and he is a year removed from a .278/.371/.505 batting line with 30 home runs. The bad news is he hit .265/.328/.412 with five home runs last year and spent much of the season in Triple-A. Santana is one of those players who's kind of useless if he's not hitting for power because his defense is pretty terrible. Still, for a team trying for a quick-fix rebuild, he's a great roll of the dice. Santana looking like 2017 Santana this spring would be awfully exciting.

OF Marcell Ozuna. Ozuna's first season with the Cardinals did not go according to plan. He hit a good but not great .280/.325/.433 with 23 home runs with defense that made you wonder how he won a Gold Glove in 2017. Ozuna played through a nagging shoulder issue though and he had offseason surgery to correct it. With a healthy shoulder, he could revert back to his .312/.376/.548 with 37 homers form from 2017. Remember, he's going to be a free agent after the season and he'll play the entire year at 28. A productive spring following shoulder surgery could help propel Ozuna to a monster contract year.

OF Kevin Kiermaier. Two years ago the Rays gave Kiermaier a six-year extension worth $53.5 million. Since then he's played only 186 of 324 possible games due to injury, and his offense slipped last year. His defense is so good that he racked up 7.6 WAR in those 186 games, but Tampa didn't give Kiermaier that contract only to get a good glove. For the Rays to make a real run at a postseason spot this year -- as successful as they were in 2018, they were never particularly close to securing a postseason spot -- they'll need Kiermaier on the field all year. That starts in the spring.

OF Nomar Mazara. In his three big league seasons Mazara has hit between .253 and .266, posted an on-base percentage between .317 and .323, and slugged between .419 and .436. That equals an OPS+ between 90 and 94. Hey, consistency is cool, but Mazara turns 24 in April and he's a former top prospect. At some point a breakout year would be nice, you know? It would be silly to give up on a player this talented and this young. It's just that he needs to show something more relatively soon to avoid going from future cornerstone to complementary player for the Rangers. A big spring training would get the hype train rolling.

SP Aaron Sanchez. It's easy to forget Sanchez led the American League with a 3.00 ERA in 2016. Injuries, including a suitcase-related ailment last year, have limited him to only 141 innings since though, and in those 141 innings he had 4.72 ERA. At his best, the 26-year-old Blue Jays hurler is a dominant strikeout/ground ball pitcher, someone with true ace ability. We just haven't seen it much these last two years. A strong and healthy spring is the first step toward Sanchez regaining his 2016 form. Also, he's only two years away from free agency. The quest for a big payday begins now.

OF Adam Eaton. In the two years since coming over from the White Sox, Eaton has played only 118 games due to various injuries. He's been great in those 118 games (.300/.394/.422), but it's only 118 games. The Nationals will need Eaton healthy and wreaking havoc atop the lineup to return to the postseason, and, for Eaton personally, this is the final guaranteed year on his contract. Washington picking up his $9.5 million option after the season will be no sure thing with another injury-filled season. Less could equal more for Eaton this spring. Less action in an effort to keep the body 100 percent going into the season.