I typically update my ranking of the top MLB players under age 25 once a year, but with this year's playoff rosters loaded with young talent, I've produced this special, shorter edition highlighting the top 10 players on these 10 clubs whose seasonal ages in 2017 were 24 or younger. Fourteen of the 25 players on my list from earlier this season are on playoff teams, and that doesn't include rookies who weren't eligible for the list last time but are now.
Also, there's no Aaron Judge here, as this was his age-25 season. This list is for players who are 25 or younger after July 1.
1. Carlos Correa, SS, Houston Astros (22)
Rank in May: 3
He might be overshadowed by his partner in the Astros' middle infield, Jose Altuve, but Correa established himself as a potential MVP candidate in his own right with a 6.1 WAR season despite missing more than 50 games because of injury.
He continued to grow into more power, he struck out less often than he did in 2016, and he played adequate defense at shortstop. His 24 homers in 109 games are a full-season pace of 35 homers. Only seven shortstops have hit at least 35 homers in a season in MLB history, with Alex Rodriguez and Ernie Banks the only shortstops to do so multiple times.
2. Bryce Harper, RF, Washington Nationals (24)
Rank in May: 1
Harper was on pace for a nearly 7 WAR campaign when an errant step on first base effectively ended his regular season, and had he qualified, his .413 OBP and .595 SLG would both have ranked third in the National League, with the latter figure behind only Giancarlo Stanton and Charlie Blackmon (who gets a power boost from Coors Field).
Harper has been incredibly productive when healthy throughout his career, but he has missed a lot of time because of injuries, mostly freak ones but enough that it has to factor into any look at his career value or near-term projection. He remains one of the most patient hitters in baseball and has otherworldly power, so he's still near the top of this list and has as good a chance to make a huge October impact as any player.
3. Corey Seager, SS, Los Angeles Dodgers (23)
Rank in May: 4
Seager, like the two players above him on this list, battled an injury this year, with inflammation in his right elbow that might require offseason surgery, yet he still managed to be among the most valuable position players in the National League, including posting the best defensive numbers of his brief career.
I do wonder if the injury sapped any of his power. In a year when players were setting career highs in homers, Seager hit fewer doubles, triples and home runs than he did in 2016, even if you adjust for the fact that he played 12 fewer games. Between that and his youth, there's likely still more power to come as Seager gets into his mid-20s.
4. Francisco Lindor, SS, Cleveland Indians (23)
Rank in May: 5
Lindor hit 21 homers in 1,880 minor league plate appearances, 27 in his first two major league seasons (1,122 PA) ... and 33 home runs this year. He already did just about everything else you could ask of a major league shortstop: He gets on base, he runs well, he's a great fielder, he has good instincts on both sides of the ball, and now he's a 30-homer guy?
I know the ball is juiced -- we all know this by now -- but even with that, I didn't expect Lindor to see 33 home runs even in a peak year. Now if we could just get him to stop bunting.
5. Mookie Betts, RF, Boston Red Sox (24)
Rank in May: 6
The Red Sox's Gold Glove-caliber right fielder is among the majors' most complete, balanced players, with a pleasing symmetry in his stat line this year: 77 walks, 79 strikeouts; 101 runs scored, 102 RBIs; 24 homers, 26 steals. (If this doesn't please you, you probably don't speak math.)
He does everything well and nothing poorly, and even though he didn't match his 2016 peak (9.5 WAR, per Baseball-Reference.com), he produced his third straight 6 WAR season. In the integrated era of MLB, his career WAR total of 24 is the 20th-best mark by any player through his age-24 season, putting him just ahead of Barry Bonds and Roberto Alomar.
6. Luis Severino, RHP, New York Yankees (23)
Rank in May: Unranked
Severino went from a 5.83 ERA and replacement-level value in 2016 to a top-five performance in the American League this year, finishing third in the league in ERA and fourth in strikeouts. The biggest change for Severino was the development of his slider, a below-average to fringe pitch for him all the way through the minors and into last season. In 2017, it was his best pitch and one of the most effective sliders from any starter in baseball.
7. Jose Ramirez, 3B/IF, Cleveland Indians (24)
Rank in May: 18
Ramirez, like Lindor, had a huge power spike this season, with 19 home runs in about two seasons' worth of PA coming into 2017 and 29 homers during this season. He also set a career high with a .374 OBP and played solid defense at third.
I think the most remarkable part of Ramirez's game, however, is his contact rate: In an era when everyone strikes out 100 times and 200 is no longer a sort of scarlet number on your Baseball-Reference page, Ramirez stuck out just 69 times, and his 10.7% K/PA rate was the fourth-lowest among qualifying hitters in either league.
8. Cody Bellinger, 1B/OF, Los Angeles Dodgers (21)
Rank in May: Ineligible
I was as high as anyone on Bellinger's upside, but I didn't expect him to hit this well and with this much power if he was even called up in 2017, which seemed unlikely before the season began.
Instead, Bellinger hit .267/.352/.581 with 39 homers, setting the NL record for home runs by a rookie and recording the third-best rookie homer total ever. He also played four positions, acquitting himself well in center and playing outstanding defense at first, Wally Pipp-ing Adrian Gonzalez and helping the Dodgers secure the best record in baseball. Bellinger didn't turn 22 until mid-July.
9. Byron Buxton, CF, Minnesota (23)
Rank in May: 8
After the Twins gave the struggling Buxton a day off on April 19 and got him to axe his big leg kick, he hit .272/.333/.446 the rest of the way, making him an above-average hitter who just happens to play world-class defense in center. Baseball-Reference valued Buxton's season at 5.1 WAR, with his defense accounting for about half of that, but if you believe that this new Buxton -- not the one who started the year 4-for-47 with 23 strikeouts -- is the real one, then you're saying he's already a star.
10. Alex Bregman, 3B/SS, Houston (23)
Rank in May: 13
Bregman is a nice case study in why we shouldn't overreact to slow starts by highly regarded prospects. He began his big league career in 2016 with no hits in his first four games and a 2-for-38 performance in his first 10 games, which dragged his slash line for the season down to .264/.313/.478. Bregman's average exit velocity wasn't great at 83.6 mph, and the power he showed in the minors wasn't apparent.
Bregman addressed most of those concerns with his performance this year, cutting his strikeout rate by more than a third, making harder contact (87.5 mph average exit velocity) and walking a little more often while playing fringe-average defense at shortstop when Correa was injured. He might never move off third as long as he's an Astro, but he could start at short or second for most other teams in the majors.
Honorable mentions: Gary Sanchez, Andrew Benintendi, Miguel Sano, Archie Bradley, Xander Bogaerts, Rafael Devers, Trea Turner, Kyle Freeland.