The Seattle Mariners have promoted top prospect Colt Emerson to the major leagues to replace an injured Brendan Donovan, who landed on the 10-day injured list with a groin issue retroactive to May 16.

Emerson, who signed an eight-year, $95 million extension in March 2024 and was the 22nd overall pick in the 2023 draft, arrives after a breakout run in 2025 across multiple levels and a strong showing in Tacoma this season.

In his MLB debut, Emerson will start at third base and bat ninth in the series finale at T-Mobile Park, signaling a longer-term development plan rather than a short-term cameo.

Donovan’s return timeline remains unclear, with an estimated two-to-three weeks possible depending on progression and daily symptoms.

The organization emphasizes Emerson’s commitment to consistency and teamwork as the foundation for his development and future contributions.

Donovan’s groin injury appears more severe than initially conveyed and echoes a prior issue linked to a sports hernia surgery last year with the Cardinals.

Mariners leadership — including GM Justin Hollander, manager Dan Wilson, and president of baseball operations Jerry Dipoto — discussed the promotion as a long-term development move rather than a short-term fix.

The decision to promote Emerson followed conversations among top leadership and field management, underscoring a strategic move toward his long-term fit with the club.

Wilson described Donovan’s injury as day-to-day, with pregame warmups guiding whether he could be available off the bench.

Matt Brash remains in rehab with Tacoma after right-lat inflammation sidelined him since early May.

Hollander called Emerson ready for the jump, noting his matter-of-fact mindset and willingness to head to Seattle immediately.

Donovan’s injury management is central as Seattle tries to avoid a sweep and salvage a win with Emerson at third base.