Every season seems to bring two sets of rookies: those who leave their marks over the full season and those who make their biggest impressions over the final two months, usually after a stretch-run callup.
The first group usually includes the main candidates for AL and NL Rookie of the Year. The second group usually doesn’t have enough playing time to qualify or make an impression for that award — and, conversely, often end up with too much playing time to qualify for the next season’s award — leaving them in a kind of rookie no man’s land as far as proper recognition. But that doesn’t mean they’re not noticed.
These “new” rookies are often able to grab our attention in a way that makes us excited about the possibilities for the next season, and that’s certainly happened in 2025. Here’s a look at seven MLB rookies whose early performances have them poised for breakouts in 2026.
All stats are through Wednesday.
Chase Burns, RHP, Reds
Key 2025 stat: 13.9 K/9 ratio in first 10 appearances (eight starts)
Burns throws triple-digit gas, has a wipeout slider and has an electric personality on the mound — all major superstar ingredients. His potential was on full display in his MLB debut on June 24, when he struck out the first five Yankees he faced en route to eight punchouts over five innings in a no-decision. But in his second start, he allowed five earned runs in one-third of an inning against the Red Sox. The rest of his season followed a similar inconsistent pattern until he went on the IL in August with a right flexor strain. He’s back now, but in the bullpen. Still, there’s been plenty to like.
Burns struck out 10 batters in four of his last five starts before his injury. He was only prevented from having five straight such outings when he pitched just one-third of an inning in the Speedway Classic before rain postponed the game. He has a 13.9 K/9 ratio, which, if he had enough innings to qualify, would far and away be the highest mark in baseball. Though he had a 5.24 ERA in 34 1/3 innings before his IL stint, a healthy and more experienced Burns in 2026 gives him the potential to become one of baseball’s most dominating pitchers.
Jeremiah Jackson, INF/OF, Orioles
Key 2025 stat: 46.8% hard-hit rate through first 40 games
The 25-year-old Jackson debuted on Aug. 1 and started hitting right away, recording three knocks in his first six at-bats. By the end of the month, he was riding a hitting streak that reached 13 games and produced a .981 OPS, showcasing the skills and potential that landed him on this list. Since his debut, his .289 average is third-best among AL rookies with at least 150 plate appearances, while his 70 total bases are tied for second. He’s had 10 multihit games since Aug. 15, including a four-RBI performance against the Giants on Aug. 30.
The hits are coming for a very basic reason: He hits the ball hard. Jackson’s 46.8 percent hard-hit rate is well above the league average of 36.9 percent and ranks second-highest among all MLB rookies with at least 150 PAs since Aug. 1. Jackson has been a late bright spot in an otherwise disappointing season for the Orioles. But as his early success shows, he could be a big part of their future as they look to return to contender status next season.
Luke Keaschall, 2B, Twins
Key 2025 stat: 131 OPS+ through first 44 games
Keaschall’s first seven big league games in April featured the kind of production that could’ve had him in the conversation for AL Rookie of Year in the months that followed: a .368 average and a 1.065 OPS. But he suffered a broken right forearm when he was hit by a pitch on April 25, which kept him out until Aug. 5. But once he returned to the Twins’ lineup, he continued to be a very productive hitter.
In the 37 games since his return, he’s hit .304 with an .809 OPS, which has given him a 131 OPS+ for the season. The consistency he’s shown is attributable to his excellent eye and strong bat-to-ball skills. Keaschall has a chase rate of just 20.1 percent, well below the MLB average of 28.4 percent, while his whiff rate is an equally impressive 18.2 percent (MLB average is 25.0 percent). So, when he swings, he tends to put the ball in play. He also has excellent sprint speed, rating in MLB’s 85th percentile, which has allowed him to swipe 13 bases, tied for fourth-most among AL rookies despite playing in just 44 games.
Jakob Marsee, OF, Marlins
Key 2025 stat: 154 OPS+ since debut on Aug. 1
Marsee has been a revelation for the Marlins. Entering play Thursday, he was hitting .317 with a .924 OPS and a 154 OPS+ through his first 45 games (189 plate appearances). The lefty slugger has been worth 2.1 bWAR during that span, which is a 7.5 WAR pace over a full season. That’s MVP-level stuff.
Since his debut Aug. 1, Marsee led all MLB rookies with at least 160 plate appearances in average, total bases (89) and stolen bases (11) entering Thursday. He also ranked second in on-base percentage (.392), second in OPS and third in hard-hit rate (44.5). The lefty has 15 multihit games, including two four-hit games, one of which produced seven RBIs against the Guardians on Aug. 13. Among all rookies with at least 180 PAs this season, Marsee’s 154 OPS+ entering Thursday was second only to A’s slugger and AL Rookie of the Year favorite Nick Kurtz (172).
Nolan McLean, RHP, Mets
Key 2025 stat: 1.19 ERA in first six starts (37 2/3 innings)
McLean came to the Mets with hype, and he has delivered. Since his debut on Aug. 16, New York’s No. 1 pitching prospect has gone 4-1 with a 1.19 ERA in six starts, the lowest ERA of any MLB pitcher with at least 30 innings pitched during that span. Not only that, but the righty’s 40 strikeouts are most among rookie hurlers since his debut, while his 0.98 WHIP and .194 opponents’ average are second only to the Cubs’ Cade Horton.
McLean has not allowed more than two runs in any of his starts and has four times held opponents to one or no runs. And it’s not like he’s been facing lackluster competition. All but one of his starts have come against teams in the playoff hunt, and the Mets are 4-1 in those games, with the only setback coming on Sept. 8, when McLean went five innings and allowed just one run in a 1-0 loss to the Phillies.
Kyle Teel, C, White Sox
Key 2025 stat: .375 on-base percentage through first 70 games
Teel is emerging as one of the more under-the-radar offensive catchers in baseball. Since his debut on June 6, the White Sox backstop leads all primary catchers with a .375 on-base percentage, while his .280 average ranks fourth and his .807 OPS ranks sixth.
He’s had five games with at least three hits, including two four-hit games. Entering Thursday, Teel had a .910 OPS in September with four homers. As good as that’s been, it actually represents a bit of a cooldown. In one 15-game stretch from Aug. 18-Sept. 4, Teel hit .400 with four homers and a 1.165 OPS. For the season, his .807 OPS and 126 OPS+ both lead the White Sox, while his 1.8 bWAR is tied for the second-highest mark on the team among position players.
Hurston Waldrep, RHP, Braves
Key 2025 stat: 1.33 ERA through first seven appearances (six starts)
Waldrep is the only player on this list who debuted before this season, but his 2024 callup was brief — just seven innings across two starts. But more importantly, when he returned to the Majors in August, he had evolved into a completely different pitcher. After more time in Triple-A, a mechanical adjustment and the incorporation of a sinker, Waldrep’s 2025 campaign has provided the Braves with a bright spot amid an otherwise disappointing season.
Starting with an emergency long-relief outing in the resumption of the rain-delayed Speedway Classic that began Aug. 2, Waldrep pitched to a 1.33 ERA in his first seven appearances (six starts), never allowing more than two runs in any outing. Though that ERA took a hit during an eight-run outing against the Astros on Sept. 12, Waldrep’s outing on Wednesday against the Nationals represented more of a return to form. He fanned eight batters and allowed three runs over five innings in a 9-4 Braves win. He’s shown enough to be a major contender for a 2026 rotation spot.
