The Seattle Mariners promoted top prospect Colt Emerson from Triple-A Tacoma to the major leagues ahead of Sunday night’s series finale against the San Diego Padres.
Mariners reveal plan for next turn through rotation
Emerson will bat ninth and start at third base in Seattle’s updated lineup for Sunday night. The 20-year-old will be the youngest Mariners player to make his MLB debut since franchise legend Félix Hernández did so at age 19 in 2005.
The Mariners also placed third baseman Brendan Donovan on the 10-day injured list with a left groin muscle strain.
Emerson, a 20-year-old shortstop, is widely viewed as one of the top prospects in all of baseball and an integral piece of the Mariners’ future. He’s ranked as the No. 3 prospect by Baseball America and the No. 6 prospect by MLB Pipeline and ESPN.
Emerson was scratched from Triple-A Tacoma’s lineup on Sunday afternoon.
Donovan, meanwhile, is headed to the IL with the same injury for the second time in a month. He spent nearly three weeks on the IL the last time around before returning on May 8.
While Emerson is viewed as Seattle’s shortstop of the future, he’s an option at third base in the short-term. He played five games at third base for Tacoma this season, in addition to 33 games at shortstop.
Emerson slashed .255/.347/.469 with seven home runs, one triple and eight doubles over his 38 games with the Rainiers this year.
Emerson was taken No. 22 overall in the first round of the 2023 draft out of John Glenn High School in New Concord, Ohio.
The left-handed-hitting shortstop impressed early in his time in the Mariners’ system, hitting .374 with 1.045 OPS, three homers and 14 doubles over 24 games across the Arizona Complex League and Single-A shortly after being drafted in 2023. He also helped Single-A Modesto win the California League title, batting .450 (11 for 20) with three doubles and eight RBIs in four playoff games.
But it was last season when Emerson started to soar though the minors.
He made the climb from High-A to Triple-A over the course of the season, needing just 34 games at the Double-A level before joining Triple-A Tacoma. In 130 games across all levels, he slashed .285/.388/.453 with an .841 OPS, 16 homers, 28 doubles, six triples and 71 walks to 105 strikeouts.
Emerson’s impressive 2025 campaign included hitting .333 (10 for 30) with two homers and two doubles in eight games with Tacoma including the Pacific Coast League playoffs.
Emerson ended up getting a chance to be around the Mariners for their player run following his stint with the Rainiers, as he was one of 12 players named to the Mariners’ taxi squad for the postseason.
After a solid showing in spring training this year, the Mariners signed Emerson to an eight-year, $95 million contract extension through the 2033 season on March 31. The deal included a ninth-year club option for 2034, a full no-trade clause and performance escalators that could make it worth over $130 million.
It’s the largest contract ever given to a player with no MLB service time.
Bat-to-ball skills and an advanced approach of the plate have been a major reason for Emerson’s pedigree as a prospect. He ran a strikeout rate of 17.5% or lower and a walk rate of 11.9% or higher in each of his first three minor league seasons.
There were questions early as to if Emerson was stick at shortstop early on in his time in the minors, but he’s since developed into a player with plus potential as a defender. MLB Pipeline recently named him as the top defensive prospect in the Mariners’ farm system.
Seattle Sports’ Cameron Van Til contributed to this post.
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