They're not just breaking into the big leagues anymore; they're breaking out. The 2025 season features a wave of under-25 stars with the production, poise, and profiles to carry teams. Here's who's making the biggest impact already. Credit: X Witt's 2024 season was historic. He led all of baseball in hits and batting average, went 30-30, and took home a Gold Glove. Oh, and he posted a 10.4 WAR—company that includes Ripken and A-Rod. Not bad for a 24-year-old shortstop. Credit: X After winning Rookie of the Year, Gunnar followed up with a season in which voters circled his name. His name's got thirty-seven homers, slick defense, and a growing reputation as the heartbeat of Baltimore's lineup. He's coming into 2025 a bit banged up, but if he finds his rhythm early, look out. Credit: X Somehow, all the hype felt justified. Skenes debuted in May and still managed to lead all qualified starters in ERA. He brought two new pitches with him and walked away with Rookie of the Year and a top-three Cy Young finish. Pittsburgh's rotation has a new anchor, and he's 22. Credit: X It wasn't his loudest year, but Julio still checked all the boxes: another 20-20 season, elite defense, and a July heater with an OPS over 1.100. A full-season breakout could be right around the corner. The Mariners are betting on it. Credit: X A shortstop by trade, Merrill slid into center field in 2024 and didn't miss a beat. He was top-10 in outs above average and nearly matched Aaron Judge in offensive output among center fielders. Padres fans should be excited, and maybe a little surprised. Credit: X De La Cruz's 25-67 season made history; no shortstop had ever hit that power-speed combo. He needs to improve his swing-and-miss tendencies, but the Reds star is already one of MLB's most dynamic athletes. Credit: X Chourio struggled early, then torched pitchers in the second half of 2024. His .914 OPS after June made him one of the league's most dangerous bats, and he remained perfect defensively all season. He followed it up with a postseason burst. Credit: Instagram It took him a while to get going, but post-All-Star break, Carroll looked like his old self: 17 homers, 17 steals in just 64 games. He reminded the league why he was an MVP finalist as a rookie. If that second-half version is here to stay, 40-40 talk is back on the table. Credit: Instagram We've always known about the fastball, but in 2024, Greene figured out how to pitch. He cut down the homers, trusted his secondaries, and kept hitters off balance. The result was a Cy Young top-10 finish and a new level of confidence. Credit: Instagram Injuries have slowed Greene before, but he stayed mostly healthy in 2024 and posted career highs across the board. His patience improved, his barrel rate climbed, and his defense stabilized. He finished as one of MLB's ten most valuable outfielders and returns as the Tigers' offensive centerpiece. Credit: Facebook After being limited by injuries the past two seasons, Harris quietly posted a 124 wRC+ and 4.6 WAR in 2024. His contact skills and power-speed mix make him a tough out and a sneaky All-Star candidate. He could just turn out to be Atlanta's next big thing. Again. Credit: Facebook Sent down early in the season, Butler came back with something to prove, and prove it he did. He smashed 20 homers after his return, including 10 in July alone. The power is real, and there's no doubt Oakland's got a legit slugger on their hands. Credit: X Langford finished strong, earning AL Player of the Month in September. His OPS surged, and projections suggest he'll be one of Texas's most valuable hitters in 2025. Credit: Reddit Originally not on the Mets' Opening Day roster, Vientos slugged 27 homers and became one of their best power threats. The key for him in 2025 is contact quality. His in-zone contact rate lags behind the league average, but if he narrows the strike zone, another jump could follow. Credit: X Still just 22, Winn is already the Cardinals' tone-setter. He led the team in WAR, played top-tier defense, and brings speed, energy, and everyday reliability. There's room for his bat to grow, but the foundation is rock solid.
