Red Sox Confirm Opening Day Plans for Top Prospects Mayer and Campbell

Infielder Marcelo Mayer makes the big league roster, while Kristian Campbell heads to Triple-A to start the season.

Mar. 21, 2026 at 11:08pm

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The Boston Red Sox have finalized their roster ahead of Opening Day, with top prospects Marcelo Mayer and Kristian Campbell figuring prominently in their plans. Mayer, the team's 2021 fourth-overall draft pick, has been told he will be the starting second baseman, while Campbell, who was Boston's Opening Day second baseman last year, has been optioned to Triple-A to continue his development.

Why it matters

The Red Sox are looking to the future with these two young infielders, who were both highly touted prospects in the organization. Their performances this season could play a big role in determining the team's direction as they aim to return to the playoffs.

The details

Mayer made his MLB debut last season, primarily playing third base before a wrist injury ended his year after 44 games. The 23-year-old impressed the Red Sox coaching staff enough this spring to earn the starting second base job. Meanwhile, Campbell, a 2023 fourth-round pick, struggled after a strong start to his rookie campaign in 2025, leading to his demotion to the minors in June. This spring, he was used exclusively in the outfield, suggesting the Red Sox may have other plans for his long-term role.

  • Mayer made his MLB debut in 2025.
  • Campbell was Boston's Opening Day second baseman in 2025.
  • Campbell was sent down to the minors in June 2025 after struggling.

The players

Marcelo Mayer

A top prospect in the Red Sox organization, Mayer was the team's fourth-overall draft pick in 2021.

Kristian Campbell

A 2023 fourth-round draft pick by the Red Sox, Campbell was the team's Opening Day second baseman in 2025 before being sent down to the minors.

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What they’re saying

“Mayer will be the Red Sox's second baseman heading into Opening Day.”

— Alex Cora, Red Sox Manager

What’s next

With a crowded outfield in Boston, Campbell should have time to continue to develop in the minors at the start of the season. Mayer will have the chance to work on his craft in the big leagues, but the Red Sox do have Caleb Durbin and Isiah Kiner-Falefa, who could shift around the infield if necessary.

The takeaway

The Red Sox are putting their faith in two of their top young prospects, Marcelo Mayer and Kristian Campbell, as they look to build for the future. While Campbell will start the season in the minors, Mayer has earned the starting second base job, giving him a chance to prove himself at the MLB level.