Seattle Mariners

Mariners promote top prospect Colt Emerson, set for MLB debut

The Seattle Mariners are promoting top prospect Colt Emerson to the major leagues, the team announced Sunday afternoon.

The 20-year-old infielder will bat ninth and make his MLB debut in Sunday’s series finale with the San Diego Padres at T-Mobile Park. First pitch is scheduled for 4:20 p.m. on NBC’s Sunday Night Baseball.

Emerson, considered the No. 6 prospect in MLB, was scratched from Triple-A Tacoma’s lineup and recalled from the Rainiers. He becomes the youngest Mariners player to make their major league debut since Felix Hernandez in 2005 (19 years old).

Emerson appeared in 38 games with the Rainiers this season, batting .255 (37-for-145) with seven home runs and 26 RBI.

“(The Mariners) preach exactly that — being consistent as a player,” Emerson told The News Tribune in March. “Just be a good teammate, and do things that help the team win. If you do that every day, you’re going to be a successful player at the end of the day.”

Emerson signed an eight-year, $95 million contract extension with the Mariners on March 31, a record figure for a player yet to make their major league debut.

In a corresponding roster move, Seattle placed infielder Brendan Donovan on the 10-day injured list (retroactive to May 16) with a left groin muscle strain — the latest in a series of injuries to key contributors (Cal Raleigh, Matt Brash, Gabe Speier).

Emerson slots into Donovan’s role at third base for Sunday’s finale with San Diego.

Tacoma Rainiers shortstop Colt Emerson (6) takes part in pre-game introductions before a game against the El Paso Chihuahuas on Tuesday, March 31, 2026, at Cheney Stadium in Tacoma, Wash.
Tacoma Rainiers shortstop Colt Emerson (6) takes part in pre-game introductions before a game against the El Paso Chihuahuas on Tuesday, March 31, 2026, at Cheney Stadium in Tacoma, Wash. Liesbeth Powers lpowers@thenewstribune.com

Seattle selected the left-handed hitting Emerson in the first round (22nd overall) of the 2023 MLB Draft. The potential infield cornerstone joins the likes of Raleigh, Julio Rodriguez, Logan Gilbert and Bryan Woo on a long list of homegrown players drafted by the Mariners.

This story was originally published May 17, 2026 at 2:47 PM with the headline "Mariners promote top prospect Colt Emerson, set for MLB debut."

Tyler Wicke
The News Tribune
Tyler Wicke joined The News Tribune in 2019 as a sports clerk. A graduate of the University of Washington Tacoma in 2021, Wicke covers the Mariners, preps, and maintains clerical duties. Was once a near-scratch golfer, but now, he’s just happy to break 80.  Support my work with a digital subscription
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