Kristian Campbell used a mirror to change his swing after a difficult rookie year

Kristian Campbell spent the offseason rebuilding his swing with mirror work, video study and winter-league at-bats after being sent to Triple-A midseason in 2025; he has shown progress in spring training and spent time with Red Sox coaches in Puerto Rico.

Kristian Campbell spent much of the offseason studying and rebuilding his swing after a difficult 2025 season. He signed a long-term extension before that year but was sent to Triple-A by mid-June and did not return to the majors. Campbell combined video work, mirror practice in his parents' living room, tee and machine work, and a winter-league stint in Puerto Rico to test changes. Red Sox coaches visited him in Puerto Rico and he has continued the work into spring training. Key details: - Campbell signed an eight-year, $60 million extension before the 2025 season. - He was sent to Triple-A in mid-June 2025 and did not return to the majors that year. - His offseason routine included video study, mirror work to lower his hands, tee work, and machine repetition. - He played 14 games for Criollos de Caguas in Puerto Rico, going 2-for-17 in the first week and 10-for-32 over his final nine games. - Over 67 major-league games in 2025 he had a 27 percent strikeout rate, hit .223 with a .664 OPS. - The team reports he added 13 pounds and opened camp at 216 pounds while working defensively in the outfield this spring. Summary: Campbell has taken a methodical approach to changing his swing and tested the adjustments in game settings during winter ball. Red Sox coaches have been involved in the process and note physical and technical progress entering spring training. He is being worked in the outfield as roster positions are sorted and several outfielders are headed to the World Baseball Classic, which could create opportunities. How the swing changes hold up in regular-season games remains to be seen.