BOSTON -- Marcelo Mayer, MLB Pipeline’s No. 5 prospect and the top-ranked prospect in Boston’s farm system, took a leap forward with a strong performance for Double-A Portland this season.

However, it appears the shortstop won’t get the chance to enjoy the fruits of the promotion to Triple-A Worcester he earned on Aug. 11. Mayer is likely to miss the remainder of the 2024 season due to a lumbar strain, a source told MLB.com.

The Boston Globe’s Alex Speier was first to report the news.

The left-handed-hitting Mayer was placed on the 7-day injured list while still at Double-A on Aug. 1, but he was activated at the time of his promotion. He has yet to play for Worcester, though, as the club continued to monitor his health. Instead of staying with the WooSox in hopes of returning to the lineup, Mayer reported to Boston’s Spring Training facility in Fort Myers, Fla., to rehab the injury.

The expectation is that Mayer will have a normal offseason and be ready for the start of Spring Training.

The latest injury brings more questions about Mayer’s durability, as this is the second straight year he hasn’t been able to finish the season. In 2023, Mayer’s season ended at Double-A on Aug. 2 due to left shoulder inflammation.

Mayer bounced back from that injury to have a big 2024 campaign with Portland. In 77 games and 335 plate appearances, Mayer had a batting line of .307/.370/.480 with 60 runs, 92 hits, 28 doubles, eight homers, 38 RBIs and 13 stolen bases. Last year, Mayer played in 78 games with 353 plate appearances.

“I mean, obviously not ideal,” said Red Sox manager Alex Cora. “He had a good season, did a good job. But honestly, I didn’t know. I'll talk to [player development] and see what happens. But getting him right is the most important thing. There's a lot of potential there. There's things that we have to work on. [The] injuries, obviously, from my end, [are] concerning, to be honest with you. Just have to make sure we can keep him healthy.”

When Mayer made the move to Triple-A earlier this month, it was a grand celebration, as he moved up along with the team’s other two top prospects in Roman Anthony (No. 2) and Kyle Teel (No. 3). A week later, No. 5 prospect Kristian Campbell got his promotion to Triple-A and has flourished since the promotion.

The Red Sox are brimming with promising position players in the upper Minors. Now they want to help Mayer get healthy enough to be the cornerstone he’s been projected as since 2021, when the Red Sox made him the fourth-overall pick of the MLB Draft.