Seattle Mariners promote top-prospect Colt Emerson to majors

Colt Emerson is no longer a prospect.

He's a Major League Baseball player and the Mariners' starting third baseman.

With Brendan Donovan out of the starting lineup for the second straight game and struggling to play on a daily basis due to complications from offseason surgery for a sports hernia, Seattle's front office needed to find a more viable option than continually starting utility player Leo Rivas at third base.

The Mariners decided to turn to Emerson, their top prospect and one of the top prospects in MLB, to fill the starting third base job, while placing Donovan on the 10-day injured list (retroactive to Saturday) with a left groin muscle strain.

The decision to place Donovan on the injured list and call up Emerson was made shortly after manager Dan Wilson met with the local media for his normal pregame session, as well as production meetings with the ESPN Radio announcers and the NBC broadcast team.

This wasn't on my bingo card this morning," general manager Justin Hollander said. "I didn't know that (Donovan) was going to be (placed on the) IL."

It wasn't on Emerson's radar either. He was preparing to play in the final game of a homestand with the Rainiers. Instead, he had a brief meeting with Tacoma manager John Russell and was told to grab his stuff and get to Seattle.

Emerson made the drive north to T-Mobile Park before the start of Sunday night's nationally televised game vs. the Padres and was immediately inserted into the starting lineup at third base and ninth in the batting order.

"It's been a crazy day," Emerson said postgame. "It sucks that we didn't get a win. But we fought, and it was a fun day."

He went 0-for-2 with two flyouts, a walk and a run scored. He also played a clean game at third base.

Hollander wasn't surprised by how Emerson handled the news of his promotion.

"He was very matter of fact," Hollander said of Emerson's reaction. "There was no jumping up and down, no celebrating. It was like, 'I'm gonna go pack my bag, I'll head right up.' He's just wired that way to handle it. Whenever it was the time that we were going to do this, I was confident Colt was going to be fine with it."

Fans have been anxiously awaiting Emerson's call-up, believing an infusion of youthful energy and athleticism was needed.

"It's not about me, it's about the team," he said. "They brought me up to help the team win."

"We want to do the right thing for Colt," Hollander said. "We also want to do the right thing for the Mariners. We think he's the best option. This period will give him some runway. This is not a 15-at-bat or a 20-at-bat tryout to see if he's capable of taking the job and running with it for the rest of the year."

The Mariners plan to play Emerson on a daily basis.

"I don't want to write the lineup out for Dan," Hollander said. "My guess is he'll play primarily third base. It's certainly not going to be in a true platoon or anything like that, whether it's every day or not, we'll still find ways to get him a day off his feet. But this also allows us to maybe get J.P. Crawford off his feet occasionally, so there'll be an occasional day at shortstop for Colt as well."

Donovan is expected to be out far longer than the 10-day minimum for an IL stint. He had recently returned from the injured list on the previous road trip. But he re-strained the groin during the series finale in Houston after almost hitting for the cycle. Donovan did pinch-hit in Friday's loss but was scratched from Saturday's game with continued discomfort.

"He ran a ton that day," Hollander said of the finale in Houston. "Between the offseason surgery and the groin strain, it's definitely related. I've talked to the (high performance) staff, they feel strongly that when you have the core surgery, you're more susceptible to groin strains and core muscle strains after that for a little bit. So he will get a PRP injection in the groin strain, as well as a different injection in the adductor, to try and keep both things working together and get them both right."

There isn't an exact timeline, but they hope Donovan can resume baseball activity in two to three weeks.

"Clearly, we need to take a step back based on how (Donovan) felt yesterday and after the Houston series and how he feels this morning," Hollander said. "We did some scans this morning and it's inflamed, it's irritated and it's back to where it was when he went on the IL the first time. So we need to get it right."

When Donovan returns, he will likely move into more of a utility role where he plays all over the field and also sees time at designated hitter.

Emerson, who doesn't turn 21 until July 20, has played in 38 games for Triple-A Tacoma this season, posting a .255/.347/.469 slash line with eight doubles, a triple, seven homers, 26 RBI, 10 stolen bases, 17 walks and 46 strikeouts in 169 plate appearances.

He got off to a slow start at the plate while dealing with some left wrist discomfort and adjusting to a higher level of competition. In his first 18 games (73 plate appearances), he posted a .258/.361/.462 slash line with six doubles, two homers, seven RBI, eight walks and 19 strikeouts. He received a cortisone injection in his left wrist and was held out of action for five days.

Over his last 15 games, he's posted a .286/.343/.524 slash line with a double, a triple, four homers, 17 RBI, four walks and 21 strikeouts in 71 plate appearances.

"He's doing all the right things," Hollander said. "What we've seen since he's come back from the cortisone shot has been really exciting. His bat speed is way up, and he's sort of back to above his norms. He's hitting the ball hard, he looks loose, he looks comfortable, he looks confident up there. 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.

The Mariners made headlines March 31, signing Emerson, who had yet to play in the big leagues, to an eight-year, $95 million contract. It was the largest contract in MLB history for a player with no big-league service time.

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This story was originally published May 17, 2026 at 4:55 PM.