MLB Pipeline will reveal its preseason list of the Top 100 Prospects on Friday, which means it's a convenient time to look back on the release of last year's list, when the Red Sox touted some of the best high-end young talent in baseball.
Heading into the 2025 season, Boston's three-headed monster of position players ranked among the game's top 12 prospects: Outfielder Roman Anthony (No. 2), infielder/outfielder Kristian Campbell (No. 7), and infielder Marcelo Mayer (No. 12) all earned recognition.
But don't expect to see any of the three on the list come Friday night: All three players have since graduated from prospect status. Anthony established himself as a franchise cornerstone and one of the game's best young players, finishing third in AL Rookie of the Year voting. Campbell and Mayer showed flashes and seem poised to compete for significant playing time come Spring Training.
Here's a look at where each of the three young phenoms stands heading into the 2026 season.
Roman Anthony
Do you remember the first 15 games of Anthony's MLB career? They weren't quite memorable: The 21-year-old began his career in a 5-for-44 funk.
It may have taken an extra week or so, but Anthony eventually proved why he debuted as MLB Pipeline's No. 1 overall prospect. Now, entering his first full Major League season, he looks like a bona fide star. He slashed .292/.396/.463, posting a 140 wRC+ (which measures a hitter's overall offensive value, compared to league average). That was tied for the 16th-best wRC+ among all hitters to have at least 200 plate appearances last season. To put that in perspective, Anthony -- who already finds himself in elite historical company -- posted a better wRC+ than perennial All-Stars like Freddie Freeman, Vladimir Guerrero Jr., and Rafael Devers.
Anthony is the rare hitter who blends exceptional plate discipline with plus power. His .396 on-base percentage was tied with Juan Soto for the fifth best in the Majors, and Soto is the superstar who perhaps best mirrors Anthony's skill set. No one hit the ball harder last season than Anthony, whose 60.3% hard-hit rate out-paced the qualifying leader, Kyle Schwarber. And it's not just what Anthony does with the bat: He totaled +6 outs above average in right field and is an above-average baserunner, skills that helped him tally 2.7 fWAR in just 71 games.
In 2026, the Red Sox will rely on Anthony to anchor their lineup. That's a tall ask for a player in their age-22 season, but Anthony isn't like most 22-year-olds: MLB Network ranked him No. 41 on their Top 100 Players Right Now list. Plus, we saw last season how Anthony changes the complexion of Boston's lineup. He suffered a season-ending oblique strain in early September, and the Red Sox struggled to score runs without him, especially in the AL Wild Card Series against the Yankees.
Kristian Campbell
Campbell's meteoric rise from fourth-round pick to one of baseball's top prospects crescendoed early last season, when he made the Opening Day roster as Boston's starting second baseman and, a few days later, inked an eight-year, $60 million contract extension. Campbell began his MLB career on a tear, carrying a .902 OPS into May.
But his hot start soon gave way to a prolonged funk, and, by mid-June, he found himself at Triple-A Worcester, where he remained for the rest of the 2025 season. In the Majors, he didn't make enough contact (with a 27.4% strikeout rate) and had trouble lifting the ball, running a 54.4% ground ball rate. He struggled in the field, too: His -10 fielding run value graded out in the third percentile of MLB.
The Red Sox instructed Campbell to add weight over the offseason, filling out his six-foot-3, 191-pound frame. The added strength figures to help Campbell make the sort of loud contact that helped him rise through the Minors. His first MLB home run left the bat at 112.2 mph, elite high-end exit velocity that underscores Campbell's ceiling. But the average exit velocity on Campbell's batted balls was just 88.6 mph, nearly a full tick below league average (89.4 mph).
It's also worth noting that Campbell entered last season having appeared in just 137 Minor League games, fewer than both Anthony and Mayer. In that vein, perhaps the reset will serve him well. In September, Campbell told MassLive that it felt like he was "redshirting" again, mirroring his freshman season at Georgia Tech. He went on to post a 1.033 OPS in his first season after the redshirt year with the Yellow Jackets. We'll see if a similar bounce-back is in store with Boston in 2026, where Campbell could become a super utility guy, capable of playing all three outfield spots. His right-handed bat will also be valuable, especially after Rob Refsnyder -- the team's lefty masher -- left for Seattle.
Marcelo Mayer
The fourth overall pick in the 2021 Draft, Mayer made his MLB debut last May in rather abrupt fashion, joining the Red Sox for the second game of a doubleheader in the wake of a quad injury to Alex Bregman. The sweet-swinging lefty went on to play 44 games in the Majors, hitting .228 with a .674 OPS (85 OPS+) before a right wrist injury ended his season in late July.
While a healthy Mayer seems poised to play a key role for Boston in 2026, it's unclear where, mostly because the Red Sox are still searching for another bat after failing to re-sign Bregman. Who that player is may very well dictate where Mayer slides in. Mayer's positional flexibility should allow Boston to pursue either a second baseman or a third baseman, whether via trade or free agency. A natural shortstop, Mayer posted +2 OAA at third base and +1 OAA at second base in a small sample size in 2025, impressing in both spots.
In the same vein as Anthony and Campbell, Mayer can hit the ball incredibly hard. He showed as much in his MLB cameo. Though he had just 87 batted balls, Mayer posted an above-average hard-hit rate (51.7%) thanks to plus bat speed, a hallmark of all three players and an emphasis of the team's player development program. The next steps for Mayer likely involve continuing to drive the ball in the air -- which he's done well in the Minors -- and improving against lefties. He had a .416 OPS against southpaws in limited time last season.
Entering his age-23 season, Mayer has already added 10 pounds to his 6-foot-3 frame, which should help him stay on the field. Much like Campbell, the Red Sox wanted Mayer to get stronger so he can better handle the workload of a full season, a challenge that all young players face. For Mayer, health is particularly paramount: He's dealt with season-ending injuries each of the last three years, and has not played more than 91 games in a season during his brief professional career. Speaking at Fenway Fest earlier this month on the Baseball Isn't Boring podcast, Mayer said that his goal was to "get as big and strong as I can."