Kristian Campbell quickly fell into lockstep with the Boston Red Sox and the big leagues after his debut. He fell out of it just as fast.
After a stellar first few weeks in the big leagues, Campbell had already signed a contract extension with Boston, batted .301/.407/.495 and netted American League Rookie of the Month honors for April. Then, he suddenly looked lost at the plate, and was demoted back to Triple-A by mid-June.
Jen McCaffrey of The Athletic interviewed Red Sox director of player development Brian Abraham about Campbell's rookie year, which he admitted did not go according to plan (subscription required). In the interview, Abraham hinted at the issue that may have plagued Campbell for the rest of the season.
“A big focus for him this offseason, he lost some weight during the year, adding some of that weight back and it’ll be getting back the strength that allowed him to impact the baseball the way he could,” Abraham said. “That allowed him to have the range in both the infield and outfield and that will be a focus.”
Red Sox to prioritize helping Kristian Campbell rebuild strength to get him back on the big league roster
The more demanding schedule and general higher intensity in the major leagues often contributes to weight loss in rookies, per McCaffrey. Campbell's weight loss adversely affected his ability to drive the baseball the same way he did in the minor leagues and in the first month of his big league tenure. He didn't fully regain his offensive footing even after his demotion to Worcester, where he batted .273/.382/.417 with a .799 OPS over 73 games.
Restoring Campbell's previous strength should help him find his swing. Abraham also noted that helping Campbell bulk up would also help improve his defensive range, which was horrific in 2025. The second baseman clocked -9 outs above average and fourth-percentile range. He was just a rookie and posted only 67 games in the big leagues, but his disastrous defense surely didn't help limit the Sox's league-leading error total. With Trevor Story's range also decreasing as his career advances, and Boston will need a stronger Campbell to his left if it hopes to remedy its defensive woes.
The Red Sox haven't confirmed which position Campbell will play in 2026, but his offseason bulking could surely be a factor in their decision. Many other considerations will also come into play, including offseason free agent signings and trades, but boosting Campbell's strength along with heightened defensive instruction in the organization should make it easier for him to find a home on the roster (subscription required).
Campbell's eight-year, $60 million contract extension kicks in in 2026, which also motivates the Red Sox to help him improve. His success in the minor leagues still shows his potential — hopefully the Red Sox properly diagnosed the issue that will help him find it in the majors.