The penultimate day of baseball's winter meetings delivered a flurry of activity, as one team rebuilt its infield, others went hard after relief pitching, and one opportunistic squad raided the cupboard of baseball's most dysfunctional franchise.

Let's break down some of Wednesday's most active teams, and grade all of the day's significant transactions.

The team: St. Louis Cardinals

What they got: Acquired OF Marcell Ozuna from Miami Marlins for P Sandy Alcantara, OF Magneuris Sierra, P Zac Gallen, and P Daniel Castano

The Grade: A-

Nabbing two years of Ozuna is a major coup. The slugging left fielder enjoyed a breakout season in 2017, batting .312/.376/.548 in a pitcher-friendly park while also winning a Gold Glove for his stellar defensive work (by Defensive Runs Saved he was the second-best left fielder in all of baseball). Ozuna just turned 27, so the two years of team control he offers should be right in his prime years, at a big discount compared to his open-market value (he made just $3.5 million in arbitration last season). Ozuna's blend of skills could add three or more wins to the Cardinals' ledger in 2018 compared to the team's other alternatives at the third outfield spot. Considering St. Louis won 83 games and finished four out of a playoff spot last year, this was the kind of aggressive move the Cards needed to make.

The Cardinals probably aren't done. Third base remains a major target, and a blockbuster deal for Josh Donaldson or Manny Machado would launch them right into the NL's elite. Meanwhile, if they can net more talent in exchange for 2017 disappointment Stephen Piscotty (the A's are reportedly closing in on a deal for him), that could make the Ozuna deal look even better. Alcantara's a talented young pitcher, but the Cards had a glut of promising pitching prospects to play with, and Alcantara's upside comes with arguably more question marks than any of the organization's other premium arms.

The team: Miami Marlins

What they got: Acquired P Sandy Alcantara, OF Magneuris Sierra, P Zac Gallen, and P Daniel Castano from St. Louis Cardinals for OF Marcell Ozuna

The Grade: B-

Alcantara can dial his fastball up over 100 mph, making him an intriguing prospect. But he's also posted sky-high walk rates over the past two seasons, and his lack of reliable secondary stuff has some talent evaluators wondering if he might be better to late-inning relief work. Even with relievers gobbling up more and more innings every year, Alcantara would be less valuable as a closer or setup man than he would be if he developed into a top-line starter. Sierra flashes great speed and excellent defense, but his weak power and plate discipline make him a question mark to stick as an everyday center fielder in the big leagues.

The good news here, at least, is that the Marlins got at least one highly regarded young player in the deal. New Marlins owner Bruce Sherman has pushed for a fire sale in an effort to pay off the debt service he incurred when he bought the team for $1.2 billion. Twenty-nine other teams are keenly aware of that fact, greatly reducing any leverage Miami might otherwise have in shopping its best players. If the Fish do move Christian Yelich as some have speculated, Marlins fans better hope their team gets full value in return; we're talking about one of the best bargain players on the planet.

The team: Los Angeles Angels

What they got: Acquired 2B Ian Kinsler from Detroit Tigers for OF Troy Montgomery and P Wilkel Hernandez

Grade: A-

Even in a down year, Kinsler still rated as the 12th-best second baseman in baseball last season. He set new career lows in batting average, OBP, and slugging with a .236/.313/.412 line. Still, Kinsler brings a lot to the table. He ranked third among major league second basemen in Defensive Runs Saved, after leading the league in that category in each of the previous three seasons. He's a plus baserunner, and he's relatively durable, with his 139 games player in 2017 marking just the second time in seven seasons that he appeared in fewer than 150 contests. Moreover, Kinsler's offensive dip might be just a blip: His hard-hit rate spiked to career-high levels last season, yet just 24.4 percent of the balls he hit in play dropped in for hits. Even at age 35, there's good reason to expect a bounceback season. With just a one-year, $10 million commitment, Kinsler's both a bargain and someone who won't weigh down the payroll long term.

Meanwhile, Montgomery ranked no. 20 on list of top Angels prospects, while Hernandez ranked 24th. The Angels haven't had a top farm system in eons, so those rankings don't bode especially well for either player's long-term outlook. Getting an above-average second baseman making less than he should for two minor leaguers who probably won't ever amount to much marks a hell of a good start to the Angels' infield-rebuilding plans. The latest rumor has the Halos going hard after third-base help, with Chase Headley a possible candidate after his recent trade to the Padres. Headley's defense has slipped and he's not much of a power threat, but he's a solid on-base guy who'd still be an upgrade over Luis Valbuena and his sub-Mendoza line efforts from last season. The Angels are a top-heavy team that had Mike Trout, Andrelton Simmons, and not much else in 2017; plus players like Kinsler and even adequate players like Headley are a must if the Halos want to fill out the rest of the roster and become true playoff contenders.

The team: Seattle Mariners

What they got: Signed P Juan Nicasio to a two-year, $17 million contract; acquired P Shawn Armstrong from Cleveland Indians for $500,000 in international bonus pool money

The Grade: B

It's Jerry Dipoto, so the Mariners probably made eight more deals while you read this sentence. In this case there's logic behind the movement, though. M's relievers ranked 17th in park-adjusted ERA last season, well behind winning teams with killer pens like Cleveland, Boston, and New York. Nicasio moves Seattle closer to the top echelon of bullpens. A converted starter, Nicasio showed a rubber arm last year in relief, ranking fifth among all relievers with 76 appearances in 2017. He's a strikeout-an-inning guy who also posted his lowest walk rate in six years, and should become an able wingman for Edwin Diaz at the back of the pen. Armstrong's brief major league track record is spottier, but the 27-year-old right-hander who punched out 12 batters per nine innings in the minors.

The M's could still use a mid-rotation starter to augment the pitching staff. But low-cost reliever moves with upside make a lot sense for a team hoping to hold their own in the AL's ongoing bullpen arms race.

The team: Houston Astros

What they got: Traded Luke Gregerson for Joe Smith

The Grade: A- (A+++++ for comedy)

It wasn't a straight-up trade, since the Astros signed Smith to a two-year deal while Gregerson left via free agency to sign with St. Louis. Still, Smith punched out 71 batters and issued just unintentional walks as part of a career year at age 33 last season. Moreover, anyone who remembers Jose Altuve's reaction to manager A.J. Hinch calling Gregerson into a key spot in last season's World Series can understand why this swap needed to happen.