I'm going to let you in on a little secret: September call-ups? Overrated.

But they're all so young and so exciting and so ... arriving at the same time. Well, you're right on two of those three points. But wrong on the most important one: Most often, they're the antithesis of exciting. They're either players we've already seen or players meant to play just a supporting role — an extra bullpen arm, a third catcher, whatever. Rarely is a team introducing its next big thing at a time no one is watching. 

Particularly in these days of efficiency-maximizing robot GMs who go to greater and greater lengths to ensure their best players are also their cheapest, what determines the arrival of a top prospect is less his own readiness than what's most economically viable. Vladimir Guerrero and Eloy Jimenez didn't come up last September, remember, and Ronald Acuna didn't the September before.

So as we're here today facing down another September, I offer a word of warning: Don't get your hopes up.

With that said ... ohmygosh, ohmygosh, ohmygosh, ohmygosh.

Those who could get the call and matter

Gavin Lux, SS, Dodgers

2018 minors: .324 BA (463 AB), 15 HR, 13 SB, .913 OPS, 57 BB, 88 K
2019 minors: .348 BA (451 AB), 26 HR, 10 SB, 1.032 OPS, 59 BB, 101 K

For a few fleeting, admittedly conflicted moments late Wednesday, it looked like Lux might be a shoo-in because Max Muncy had broken his wrist. The X-rays came back negative (which was of course great news!), but the bottom line is it shouldn't matter. The Dodgers have lost the past two World Series. They're heavy favorites to go back. They can't lose a third while the most productive minor-leaguer of the second half is at home. It'd be completely anti-competitive not to give him at least a chance to become Corey Seager's double-player partner when the division is already in hand and the opening is as plain as day given how hard they've faded Joc Pederson in recent weeks. Move Muncy to first, Cody Bellinger to the outfield and be done with it.

Kyle Tucker, OF, Astros

2018 minors: .332 BA (407 AB), 24 HR, 20 SB, .989 OPS, 48 BB, 84 K
2019 minors: .264 BA (455 AB), 33 HR, 30 SB, .905 OPS, 60 BB, 116 K 

No official announcement has been made, but beat writers like Brian McTaggart of MLB.com have suggested it's more a foregone conclusion than a matter of great suspense that the fifth 30/30 man in PCL history will be up for the start of September. And Tucker has proven twice over now he deserves this chance, his brief foray last summer hardly qualifying as a fair shake. What's most significant is that there appears to be a place for him to audition with resident space-filler Josh Reddick more or less just filling space so far in the second half. Like the Dodgers, the Astros have their division mostly locked up already and are the favorites to win their league. It makes too much sense for them to explore whether Tucker can be a difference-maker in the playoffs.

Jesus Luzardo, SP, Athletics

2018 minors: 10-5, 2.88 ERA, 1.09 WHIP, 109.1 IP, 30 BB, 129 K 
2019 minors: 2-1, 2.68 ERA, 1.03 WHIP, 37 IP, 8 BB, 47 K

Luzardo's opening isn't so obvious given that the Athletics have managed to cobble together a respectable starting five through a collection of castoffs, but he's the ace they should have had from the get-go. A strained rotator cuff ended his chances of making the opening day roster, and a strained lat prevented a midseason return. But he's back to overpowering minor-leaguers with three dominant pitches and could use some more innings before the season is done. If the Athletics could only see Homer Bailey for what he truly is, then Luzardo's impact would be similar to the one Walker Buehler had for the Dodgers last year, just coming a couple months later.

Nate Lowe, 1B, Rays

2019 minors: .290 BA (328 AB), 16 HR, 24 2B, .926 OPS, 68 BB, 81 K      
2019 majors: .294 BA (102 AB), 5 HR, 7 2B, .875 OPS, 10 BB, 29 K

Lowe looked like he was beginning to click when the Rays unceremoniously sent him down at the end of July, presumably because, among their many corner infield options, he was the one who still had minor-league options. They won't be feeling that roster crunch in September, which makes it a prime time for the presumptive favorite next spring to put to end any and all doubts. The bat skills — low strikeout rate, all-fields approach — have long been there, and the power breakthrough from the past couple years has really brought it all together, giving him the outlook, at least in my personal opinion, of a stud. It may not happen right away, but over the course of a month, he'll render Ji-Man Choi obsolete.

Ryan Mountcastle, 3B, Orioles

2018 minors: .297 BA (394 AB), 13 HR, 19 2B, .806 OPS, 26 BB, 79 K 
2019 minors: .309 BA (505 AB), 25 HR, 35 2B, .871 OPS, 22 BB, 125 K

It's probably a coin flip whether Mountcastle gets the call. The Orioles have nothing to gain in the standings, of course, but he's not the sort of face-of-the-franchise type who would normally fall victim to service-time manipulation. And most importantly, he's earned it, performing at the maximum extent of his upside in a full season at Triple-A, where the long purported power has played up big time. The poor plate discipline will limit his ceiling, but the all-around bat skills could give him a Nicholas Castellanos-type impact (albeit most likely at first base) down the stretch.

Those who could get the call but won't matter

Carter Kieboom, SS, Nationals

2018 minors: .280 BA (493 AB), 16 HR, 31 2B, .801 OPS, 58 BB, 109 K 
2019 minors: .305 BA (397 AB), 16 HR, 24 2B, .914 OPS, 67 BB, 95 K

The Nationals already popped the lid on Kieboom when they weren't sure how to handle Trea Turner's broken finger back in April, so it wouldn't hurt to give him a little more major-league exposure, especially since he had the season everyone hoped he would have at Triple-A. But you can't look back at how disastrous those two weeks he spent in the majors were, both offensively and defensively, and assume the Nationals will feel comfortable giving him meaningful at-bats as they're fighting a wild card spot. They have three competent second base options in Brian Dozier, Asdrubal Cabrera and Howie Kendrick and would presumably want Kieboom, their likely starter next year, to play more of an apprenticeship role.

Clint Frazier, OF, Yankees

2019 minors: .245 BA (233 AB), 7 HR, 19 2B, .728 OPS, 16 BB, 51 K   
2019 majors: .283 BA (191 AB), 11 HR, 11 2B, .843 OPS, 13 BB, 59 K

Manager Aaron Boone said Wednesday that Frazier would "probably' be back up in September, which would make it his first stint in the big leagues since filling in for Giancarlo Stanton every day in mid-June. The problem with that timeline is that the Yankees lost Stanton again soon thereafter and then lost Aaron Hicks and Luke Voit in the weeks that followed. Mike Tauchman, Cameron Maybin and Mike Ford all got a shot before Frazier, which would suggest the former top prospect has fallen out of favor. It can't be because of any minor-league struggles. The major-league production, which has always been solid, would count for more at this point. Presumably, some defensive lapses have made him too much of a liability for a team with the Yankees' aspirations, and I don't see why it'd change in September.

Brusdar Graterol, SP, Twins

2018 minors: 8-4, 2.74 ERA, 1.15 WHIP, 102 IP, 28 BB, 107 K   
2019 minors: 6-0, 1.95 ERA, 1.00 WHIP, 60 IP, 23 BB, 59 K

Armed with a triple-digit fastball and wipeout slider, Graterol is expected, at least in the years ahead, to join up with Jose Berrios to give the Twins a dominant 1-2 punch at the top of their rotation. But after the 21-year-old missed 2 1/2 months with a shoulder injury, not making it back until August, the Twins decided they should just audition him for the big-league bullpen rather than futilely try to stretch him back out. And it's gone ... OK. He's moved from Double-A to Triple-A, striking out about a batter per inning. They could use another arm, I guess, but would he have the sort of high-leverage role needed to make an actual impact in Fantasy? Probably not. And the same goes for Deivi Garcia of the Yankees, presuming he gets the call.

Bobby Dalbec, 3B, Red Sox

2018 minors: .257 BA (455 AB), 32 HR, 35 2B, .919 OPS, 66 BB, 176 K  
2019 minors: .243 BA (445 AB), 26 HR, 19 2B, .832 OPS, 71 BB, 132 K

The Red Sox are expected to have an opening at first base next year, and though Michael Chavis and Sam Travis are more logical choices to fill it, Dalbec probably has the most upside of the bunch as another type of ... well, comparisons to Joey Gallo and Pete Alonso would be overstating the case. But basically, he's a three-true-outcomes type with big power, good plate discipline and low batting average potential. With so many more established first base options in the mix, though (including impending free agent Mitch Moreland), Dalbec shouldn't expect more than a cameo role down the stretch.

Zack Collins, C, White Sox

2018 minors: .234 BA (418 AB), 15 HR, 24 2B, .786 OPS, 101 BB, 158 K    
2019 minors: .293 BA (283 AB), 19 HR, 19 2B, .975 OPS, 57 BB, 92 K

Collins is one of those prospective call-ups we've already seen, and what we saw wasn't pretty. He went 2 for 26 for about a three-week stretch as a backup this summer. But what makes his prospective return a matter of some interest are the strides he has made since that first big-league stint, which the White Sox claim was all for the sake of driving home the point that his ultra patient approach simply wouldn't work at the highest level. Message received. He's batting .365 (42 for 115) with 10 homers, a 1.177 OPS and just a 17.1 percent strikeout rate since returning to the minors. So ... stock up for the long haul, but yeah, he's not unseating James McCann just yet.

Those who probably won't get the call

Luis Robert, OF, White Sox

2018 minors: .269 BA (186 AB), 0 HR, 11 2B, 15 SB, .694 OPS, 12 BB, 52 K
2019 minors: .331 BA (484 AB), 31 HR, 36 SB, 1.009 OPS, 28 BB, 126 K  

For weeks, I've been saying Robert is one of the top five prospects to stash in redraft leagues, and I'm not necessarily retracting that idea by including him here. It was always a long shot he'd get the call. The White Sox have nothing to play for, and they've already given us some insight into their way of thinking with their handling of Eloy Jimenez last September. But for the minors' most impressive performer from start to finish this year, you want to be the beneficiary if there's even a remote chance he gets the call. In the end, though, I just don't think the opportunity to assess Robert's readiness for 2020 will be captivating enough for the White Sox to risk forfeiting a year of control.

Jo Adell, OF, Angels

2018 minors: .290 BA (396 AB), 20 HR, 15 SB, .897 OPS, 32 BB, 111 K   
2019 minors: .294 BA (289 AB), 10 HR, 7 SB, .851 OPS, 28 BB, 86 K 

Mike DiGiovanna of the Los Angeles Times reported in mid-August that the Angels had no plans of promoting their top prospect in September, and with the way Adell has scuffled with his move up to Triple-A, failing to homer while striking out at an unpalatable rate through 23 games, it doesn't make sense to rush the 20-year-old. A big spring could put him on the fast track next year, though, especially since there's no guarantee Kole Calhoun will still be in the mix.

Ian Anderson, SP, Braves

2018 minors: 4-7, 2.49 ERA, 1.14 WHIP, 119 1/3 IP, 49 BB, 142 K   
2019 minors: 8-7, 3.13 ERA, 1.20 WHIP, 132 1/3 IP, 59 BB, 170 K

As impressive as Mike Soroka is, Anderson has a more traditional ace profile and may well turn out to be the most important player the Braves acquired during their rebuild. But his recent move up to Triple-A hasn't gone without incident, and seeing as he has already set a career high for innings, it's not like anything he'd do in September would make him a candidate for a postseason roster spot — not in my estimation, anyway. It probably makes more sense for them to introduce him next year.

Dylan Carlson, OF, Cardinals

2018 minors: .246 BA (423 AB), 11 HR, 8 SB, .738 OPS, 62 BB, 88 K  
2019 minors: .291 BA (470 AB), 24 HR, 18 SB, .903 OPS, 57 BB, 111 K

One of the biggest risers up the prospect ranks this year has actually made a smooth transition to Triple-A, but it's been a brief one. According to Derrick Goold of the St. Louis Post-Dispatch, promoting him to the big leagues would create a 40-man issue this offseason, and frankly, the Cardinals have too many outfielders pushing for at-bats right now as it is. It doesn't mean they won't free up a spot for Carlson when his time comes, but now doesn't seem like that time.

Sean Murphy, C, Athletics

2018 minors: .285 BA (270 AB), 8 HR, 27 2B, .850 OPS, 26 BB, 50 K   
2019 minors: .303 BA (142 AB), 11 HR, 8 2B, 1.002 OPS, 22 BB, 35 K

If not for all the time he lost to a torn meniscus — two separate IL stints, it turns out — Murphy might already be a fixture in the Athletics lineup. But seeing as he's played in only 19 games since April, it'd be unfair to thrust him into a playoff race, as a third catcher or otherwise. They're reportedly considering it, but ... nah. Between the injuries, he has had an offensive breakthrough of sorts, which would suggest big things are in store for a catcher already regarded as a plus defender.