When Is Marcelo Mayer Getting Called Up? Fantasy Baseball Prospect Outlook (Week 6 Update)

When is Marcelo Mayer getting called up? Will Mayer get promoted in May 2025? Read about this top fantasy baseball prospect outlook heading into Week 6.

Boston Red Sox top prospect Marcelo Mayer is putting together a very strong season in Triple-A, and if he stays healthy, he could force his way onto the Major League roster by midseason. He has battled a variety of injuries over the last few seasons, but he has been productive when available and taken his power to new levels in 2025.

While he may not need to be stashed in standard leagues quite yet, he could make a huge impact when he arrives and be a top option at shortstop or wherever the Red Sox find a spot to slide him into the lineup.

But when are the Red Sox going to call up Mayer? Can we expect him to make his debut this summer? Let's dive in and find out. 

• Fantasy baseball trade analyzer
• BvP matchups data (Batter vs. Pitcher)
• PvB matchups data (Pitcher vs. Batter)
• Who should I start? Fantasy baseball comparisons
• Daily MLB starting lineups
• Fantasy baseball closer depth charts
• Fantasy Baseball live scoreboard
• Fantasy baseball injury reports

Marcelo Mayer Prospect Update for Fantasy Baseball

Mayer was ranked No. 3 in Boston's farm system and No. 9 overall in all of Major League Baseball by MLB Pipeline coming into the season. The Red Sox initially drafted Mayer with the No. 4 overall pick in the 2021 draft, and the 22-year-old has climbed through the minor-league ranks slowly but steadily.

He had a strong spring training, hitting .333 with one home run and a .435 wOBA, but the Red Sox still opted to have Mayer start the season at Triple-A in Worcester.

In Worcester, Mayer has played 29 games this year and is hitting .267 with a .354 wOBA. He has already hit seven home runs this season after hitting eight home runs in more than twice as many games last year in Double-A.

Marcelo Mayer is UNREAL!

Three-run home run and the Boston Red Sox prospect is now hitting .275 with SEVEN homers and 34 RBI in Triple-A this season. pic.twitter.com/XZMTsoYpwY

— Hunter Noll (@Hunter_Noll) April 27, 2025

Mayer is known as a five-tool prospect, and it's been great to see his power blossom this season. He doesn't steal many bases but brings plenty of upside in all other offensive categories.

Over the last 15 games, Mayer is 20-for-59 (.339) with four doubles, five home runs, a .452 wOBA, and an impressive 24 RBI in those 15 contests.

Marcelo Mayer Outlook for Fantasy Baseball

There is no prominent spot for Mayer to slide into the Red Sox lineup with Trevor Story currently locked into the shortstop role daily. The positional flexibility of Mayer's former fellow-prospect Kristian Campbell could allow Mayer to slot in at 2B, or the Red Sox could give him the shortstop job and move Story to second base as they did in the past when Xander Bogaerts was on the roster. Mayer should be excellent defensively wherever he gets the chance.

Marcelo Mayer being Marcelo Mayer 🤷 pic.twitter.com/3qYGNY8SzZ

— Worcester Red Sox (@WooSox) May 6, 2025

Campbell could move to the outfield, but the Red Sox also have Roman Anthony knocking on the door, creating a little bit of a log jam for playing time. It's a good thing for the Red Sox as a team, but it does complicate their prospects' fantasy timeline.

One injury can change the roster situation quickly, so be ready to add Mayer when he gets the call-up. As of right now, it looks like that will happen later this summer, as you can see from his ETA below.

Top Prospect Rankings and Call-Up ETAs

You can also check out the rest of RotoBaller's fantasy baseball prospect rankings. Eric Cross updates the below rankings weekly for the top impact prospects for 2025, and when they may be called up:

More Fantasy Baseball Advice