For many players, adjustments are needed to go from the upper Minors to facing the best players in the world. Before eventually finding MLB success, some players need everyday reps, changes to their pitch mix or approach at the plate or even a demotion back to the Minors. It's a delicate process that takes players through many ups and downs while they try to find their place in the big leagues.
So far in 2023, we've seen many of those players make that transition and transform themselves into legitimate MLB-caliber players.
Here are 10 former Top 100 MLB Pipeline prospects who have taken flight and established themselves at the MLB level. Included with each player is their highest prospect ranking according to Pipeline.
The following stats are through Tuesday's games.
Nolan Gorman, Cardinals
No. 33 prospect prior to 2022
Gorman more than held his own as a 22-year-old in his 2022 debut season with a 107 wRC+. Fast forward a year and Gorman has ascended to become one of the top hitters in the Majors. On a team with names like Paul Goldschmidt, Nolan Arenado, and Willson Contreras, Gorman is the Cards' best hitter with his team-leading 172 wRC+, 13 home runs and .622 SLG. Gorman has all but earned every bit of his production; he ranks in the 90th percentile or better in expected wOBA, expected slugging% and barrel rate. Put simply, Gorman has showcased the type of elite pop that should make him one of the better hitters in baseball for the foreseeable future.
Mitch Keller, Pirates
No. 16 prospect prior to '18
Keller's transformation from one of the worst MLB starting pitchers to one of the best has been nothing short of incredible. Since a brief demotion to the bullpen in May 2022, Keller has taken off as a frontline starting pitcher and approached his lofty prospect expectations. Through 10 starts in '23, he's a top-10 qualified starter by both ERA (2.44) and WAR (1.8). Beyond normal maturation and learning from his initial failures, Keller benefitted from offseason work at Tread Athletics following the '21 season that led to a velocity bump, a nasty new sweeper and sinker, and an overall ability to attack the zone more.
Jarred Kelenic, Mariners
No. 4 prospect prior to 2021
Kelenic was viewed as an elite franchise-cornerstone prospect prior to being promoted to the Majors in the 2021 season. He struggled mightily across his first two seasons, posting the worst batting average (.168) and third-worst on-base% (.251) among the 298 hitters with at least 500 plate appearances in that time. Kelenic flipped the script and emerged as one of the best hitters in '23. Thanks to a new swing and adjustment to his body and mind, Kelenic has tapped into his potential and ranks as a top-20 hitter (min. 100 PA) in both wRC+ (152) and SLG (.556).
Josh Lowe, Rays
No. 50 prospect prior to 2022
Lowe is one of many Rays who has taken a huge step forward and aided in Tampa Bay's historic offensive pace. After struggling in roughly 200 plate appearances in 2022, Lowe came into the '23 season with a new sense of confidence and a slightly altered swing/stance. Among hitters with at least 100 plate appearances, Lowe ranks fourth in wRC+ (173) and is tied for fifth in WAR (2.0). The changes that have led to this success look sustainable; Lowe shaved his strikeout rate by nearly 10% and has started pulling more hard-hit baseballs.
Orlando Arcia, Braves
No. 6 prospect prior to 2016
After debuting as a 21-year-old for the Brewers in 2016, Arcia never quite reached his top prospect expectations and established himself as a fine utility player. Seven years later, Arcia is producing at a rate that he's never remotely approached in the Majors. Following the offseason departure of Dansby Swanson and winning the shortstop job over Vaughn Grissom, Arcia is hitting .319/.373/.521 with a career-best 142 wRC+ in '23. He's already eclipsed 1 WAR, just the second time he's done so in his career, and is well on his way to blowing past his career-best 2.0 WAR in '17. Arcia's changes look real; he's more than doubled his career barrel rate and is making hard contact (95+ mph exit velocity) roughly half of the time.
MacKenzie Gore, Nationals
No. 5 prospect prior to 2020
Gore has been on quite the journey over the last half-decade. After ranking as a top-10 prospect in consecutive years from 2020-21, Gore struggled with performance and injuries in the Padres organization (both in the Minors and Majors) before he was included in the blockbuster deal for Juan Soto last August. With a clean slate of health in '23, Gore has taken off and produced as a legitimate big league starter for a rebuilding Nats team. In nine starts, he has a 3.88 ERA, 0.9 WAR and has struck out 28.3% of opposing hitters. Too many walks (27 in 51 innings) is something Gore will need to clean up but the fact that he's healthy and producing in the big leagues is a huge development.
Jarren Duran, Red Sox
No. 85 prospect prior to 2022
Duran has had one of the most drastic turnarounds of any position player in the Majors. Across 335 plate appearances from 2021-22, he hit .219/.269/.354 and was below replacement level. In '23, Duran is hitting .310/.364/.500 with a 132 wRC+ that ranks in the top 50 (min. 100 PA) and is tied with players such as J.D. Martinez and Adolis García. While some of this is fueled by an unsustainable .407 BABIP, he has made major strides by significantly lowering his whiff and chase rates and getting more hard-hit baseballs in the air. At 26 years old, Duran looks like he's turning into a viable everyday option for the Red Sox.
Brandon Marsh, Phillies
No. 53 prospect prior to 2021
Marsh, who was acquired in a Deadline deal last August from the Angels, has made wholesale changes in '23 that have taken him from a fringey, defense-first starter to a legitimate everyday guy in Philly. With a new stance and significantly better approach at the plate, the 25-year-old fixed some of the flaws that held him back while he was with the Angels. By trimming his whiffs and chases, Marsh has more than doubled his walk rate in '23 and has a .381 OBP that trails only 23 hitters (min. 100 PA). Marsh has overperformed his underlying offensive numbers but even if he's closer to a league-average hitter, he's a great full-time starter with his plus defense in center field as long as he can remain healthy.
Ezequiel Duran, Rangers
No. 83 prospect prior to 2022
Duran, who was acquired by Texas in the Joey Gallo trade, deserves a lot of credit for the Rangers' hot start to the season. Filling in for the injured Corey Seager (who missed over a month), Duran did his best power-hitting shortstop impression by crushing baseballs among the league's best. With Seager back in the fold, Duran now finds himself as a valuable utility player who can play all over the field (five different positions in '23). He also has shown a new offensive level: His 134 wRC+ is a top-50 figure (min. 100 plate appearances) and his .373 xwOBA backs up his offensive gains. Duran's poor whiff and chase rates will force him to make some adjustments, but he's shown that he belongs in the Majors.
Josiah Gray, Nationals
No. 58 prospect prior to 2021
Gray scuffled in his first two MLB seasons from 2021-22; his 5.17 ERA was eighth-worst among the 114 pitchers with at least 200 innings pitched. His 38 home runs allowed in '22 were the most of any pitcher in baseball. Gray has reversed course in '23 by posting a top-30 ERA (2.65) and HR/9 rate (0.78) among starters with at least 30 innings pitched. He's mostly done so by adding an effective new cutter into the mix, nearly shaving his barrel rate in half and reducing his fly-ball rate by 9.6 percentage points in '23, the largest decrease by any starting pitcher this year. He's had some luck on his side -- his expected ERA and FIP have him much closer to a 4 ERA, but even if that's the case, he's a valuable starting pitcher and a big improvement over the previous version.