The Boston Red Sox began spring training with three of baseball’s top prospects competing for a spot on the team. While a case could have been made for each of the “Big 3” – Kristian Campbell, Roman Anthony and Marcelo Mayer – it was Campbell who made Boston’s Opening Day roster.

The 22-year-old rookie, who had been ranked seventh overall among MLB prospects entering the season, won the starting job at second base. But after persistent struggles at the plate over the last month and a half, the Red Sox decided to send Campbell to Triple-A, according to ESPN’s Jeff Passan on X.

The Red Sox hope Kristian Campbell can retool in the minors

Jun 8, 2025; Bronx, New York, USA; Boston Red Sox second baseman Kristian Campbell (28) hits a two-run home run against the New York Yankees during the fifth inning at Yankee Stadium.
John Jones-Imagn Images

Campbell initially lived up to fans’ lofty expectations, getting off to an excellent start in the majors. From the beginning of the season through the end of April, Campbell slashed .301/.407/.495 – producing an even-better-than-anticipated .902 OPS. He had four home runs, 12 RBI and 18 runs scored in his first 29 games with the Red Sox.

Boston rewarded the hot start by signing Campbell to a $60 million extension over eight years. The new contract signaled the team’s faith in the rising star, tying him to the franchise through the 2034 season.

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However, in the 38 games that followed his auspicious start, from May 1 through June 18, Campbell struggled. He slashed a paltry .159/.243/.222 with two homers, nine RBI and six runs scored. Predictably, his walk rate plummeted while his strikeout rate rose.

The Red Sox were hoping the talented rookie could work through the slump, make an adjustment and return to his early-season form. But Campbell’s June swoon forced the team’s hand. Over his last week before being optioned to the minors, he hit .111 with a .440 OPS. He had just two hits over his last eight games.

Now Campbell will have the opportunity to work on his swing with the Red Sox’s Triple-A affiliate in Worcester. Chances are, he’ll be back with the big league club before too long as the talent is clearly there.

And Campbell isn’t the only member of the Red Sox’s “Big 3” prospects to struggle in the majors. Anthony and Mayer both eventually made their way to Boston this season. While Mayer has more or less held his own through 21 games, Anthony is batting .074 with a .416 OPS.