Mayer (knee) is expected to rejoin Boston's Grapefruit League lineup Tuesday against Atlanta, Jen McCaffrey of The Athletic reports.
The 22-year-old was scratched from Sunday's spring lineup due to left knee soreness and will rest again Monday, but the injury doesn't appear to be a serious concern. After posting a .674 OPS in 44 regular-season games as a rookie last season, Mayer's .816 OPS through 27 plate appearances in spring training put him in strong position to win the starting job at second base to begin 2026.