Mariners Call Up Top Prospect Colt Emerson, Place Brendan Donovan on IL

The Seattle Mariners made a significant roster move on Sunday, promoting their top prospect, Colt Emerson, from Triple-A Tacoma while placing All-Star utilityman Brendan Donovan on the 10-day injured list due to a left groin muscle strain.

Emerson, just 20 years old, was initially slated to play for the Rainiers in their home game against Sugar Land but was scratched shortly before the first pitch. Instead, he made the quick drive to Seattle, where he will become the youngest Mariners player to debut since Félix Hernández, who made his first appearance at 19 years old back on August 4, 2005.

General manager Justin Hollander admitted that the decision to call up Emerson was unexpected. “I probably wouldn’t have taken the kids tidepooling in Deception Pass (State Park) this morning,” he joked. “But, we want to do the right thing for Colt. We also want to do the right thing for the Mariners. We think he’s the best option. This period will get him some runway. This is not a 15 at-bat or 20 at-bat tryout to see if he’s capable of taking the job and running with it for the rest of the year.”

Although Emerson is viewed as the shortstop of the future for the Mariners, he will initially play third base, a position he has already started five games at for the Rainiers this season. Meanwhile, J.P. Crawford, the longest-tenured player on Seattle’s roster, will continue to serve as the everyday shortstop. Crawford, who began the season on the injured list with a right shoulder issue, is currently hitting .217 with six home runs in 39 games.

The decision to promote Emerson came after a morning meeting between Hollander, manager Dan Wilson, and president of baseball operations Jerry Dipoto. Emerson, who signed a historic $95 million, eight-year contract on April 1, was selected 22nd overall in the 2023 draft and has consistently improved his stock since then.

In 2025, Emerson had a standout season, batting .285 with an .842 OPS, 16 home runs, 28 doubles, and 78 RBIs across three levels, showcasing himself as a big league-caliber defender. This season in Tacoma, he has posted a .255 batting average with an .816 OPS, seven home runs, eight doubles, and 26 RBIs. After a slow start due to a wrist injury, Hollander noted that a cortisone shot has helped him regain his form at the plate. “He looks loose, he looks comfortable, he looks confident up there,” Hollander said. “He’s starting to put together quality at-bat after quality at-bat. There’s no reason that can’t translate over to what happens on this field out here.”

As for Donovan, he missed Saturday’s game due to his persistent left groin injury, which he had previously aggravated while attempting to hit for the cycle in an 8-3 win over the Houston Astros on Thursday. Donovan will receive a platelet-rich plasma (PRP) injection for his groin strain, along with another injection in his adductor. While there is no definitive timeline for his return, Hollander estimated it could take two to three weeks.

Donovan has had a history of groin issues, having missed time earlier in the season and undergoing sports hernia surgery in October 2025. Hollander acknowledged that the Mariners’ sports performance team had anticipated that these past surgeries could make Donovan more vulnerable to groin and core muscle strains. “Our own internal view was that there would be some days where he didn’t feel good, at least for the first half of the season,” Hollander said. “I think the most important thing that we can do is that we’re putting him in position to go out there and feel good every day.”

Note: This recap is an independently written summary based on publicly available reporting.