Red Sox finally answer Marcelo Mayer question ahead of Opening Day

With the start of the 2026 season less than a week away, the Boston Red Sox have finally made one of their biggest roster decisions.

Red Sox manager Alex Cora announced on Saturday that Marcelo Mayer will begin the year as the team's starting second baseman. Kristian Campbell, who was Boston's starting second baseman on Opening Day in 2025, has been optioned to Triple-A.

Mayer, 23, was drafted fourth overall by the Red Sox in 2021. He was viewed by many as the top overall prospect in his draft class. Mayer made his MLB debut in May 2025 after Alex Bregman suffered an injury, and the results were mixed.

Marcelo Mayer had a frustrating first season

Though he is viewed as one of the most physically gifted young players in baseball, Mayer struggled at the plate for stretches last season. He hit just .228 with four home runs and 10 RBI in 44 games.

Mayer is viewed as an excellent defensive player, which is one reason he always had a strong chance of making the MLB roster out of the gate in 2026. He is a natural shortstop but can play multiple positions, which he showed in 2025 when he was a fill-in at third base. Mayer will begin this season as a second baseman, but his versatility will give Cora flexibility to tweak lineups.

Marcelo Mayer had to earn his spot

While most fans are not surprised that Mayer has made the Opening Day roster, Cora clearly wanted the young infielder to earn his spot. The manager said as recently as two weeks ago that Mayer was not a lock to make the team out of spring training.

It seemed like Cora wanted to send Mayer a message about work ethic, and the message may have been received. Mayer has to become more consistent at the plate in order to live up to his high ceiling. For now, the Red Sox are hoping he will help them win games with his glove while showing progress at the plate.