By the time Campbell arrived in Triple-A Worcester for the season’s final month, he had ensured that the Big 3 prospect group of Roman Anthony, Marcelo Mayer and Kyle Teel was now a Big 4, and his remarkable performance across three levels was rewarded with Baseball America Minor League Player of the Year honors.
Heading into the 2025 season, the consensus was that Campbell would spend the beginning part of the year getting a little more seasoning at Triple-A, as he had received just 85 plate appearances at the level in 2024. Yet, while many assumed that Alex Bregman signed with the Red Sox to play second base, the fact that he was going to stick at third base opened up the keystone position for Campbell, who would win the job out of camp despite largely unimpressive numbers.
Much like he did in Greenville in 2024, Campbell would make headlines in the season’s opening week. He hit his first MLB home run in his third career game and finished his first week with a .429/.500/.833 line. Though he understandably couldn’t sustain that incredible pace, Campbell was still hitting over .300 by the time the calendar flipped to May, helping him take home the American League Rookie of the Month Award.
In the middle of that hitting rampage, the Red Sox announced that they had signed Campbell to an eight-year, $70 million extension. The deal, which could go as long as 10 years if a pair of club options were picked up, was a startling show of confidence in a player with less than a month of big league experience and a clear sign that the Red Sox considered him a core piece of their long-term plans.
As quickly as Campbell’s star had risen, however, it all fell apart. He hit just .134/.184/.171 in 87 May plate appearances, striking out 24 times and registering just one extra-base hit. On defense, Campbell appeared overwhelmed with the speed of the major league game, and his -8 Outs Above Average at second base was tied for the third-worst mark in all of baseball.
Given that Campbell ranked 181st out of 181 qualified hitters in OPS in May, it wouldn’t take much for him to improve in his third month in MLB. Yet while his .205/.340/.318 slashline represented a slight uptick in production, it was still a far cry from his April rampage, and it certainly wasn’t enough to overcome his defensive issues. The Red Sox finally decided that they had seen enough, demoting him to Triple-A Worcester on June 19.