Seattle Mariners activate Logan Gilbert, option bullpen arm

Logan Gilbert is officially back on the Seattle Mariners roster and set to make his first big league start in almost two months.

Mariners’ Dipoto on early trade deadline moves: ‘I think we’ll do that again’

The Mariners activated Gilbert from the 15-day injured list on Monday afternoon, optioning right-handed relief pitcher Jackson Kowar to Triple-A Tacoma to make room on the 26-man active roster. As manager Dan Wilson announced Sunday, Gilbert will start for the Mariners in a 6:40 p.m. Monday series opener at T-Mobile Park against the Boston Red Sox.

Gilbert, a 2024 All-Star and the Mariners’ opening starter this year, was placed on the IL in late April with a right elbow flexor strain.

Red Sox — next M’s opponent — send Devers to Giants in blockbuster trade

Prior to the injury, the 28-year-old Gilbert was off to a great start this season. He has a 2.37 ERA and 0.791 WHIP in six starts (30 1/3 innings), with 44 strikeouts to just six walks.

In a rehab assignment with Tacoma this month, Gilbert pitched 9 2/3 innings over three starts, allowing three runs on eight hits and four walks with 11 strikeouts.

Last year, Gilbert led the major leagues with 208 2/3 innings pitched and a 0.887 WHIP, and had a 3.23 ERA in 33 starts. He finished sixth in the American League Cy Young Award voting.

The return of Gilbert brings the Mariners’ pitching staff much closer to full strength. George Kirby, a 2023 All-Star, returned in late May after missing the first two months of the season with shoulder inflammation. Seattle also has Bryan Woo (3.39 ERA) and three-time All-Star Luis Castillo (3.29 ERA) in the rotation along with Emerson Hancock (4.48), who is filling in for Bryce Miller (15-day injured list, right elbow inflammation).

The 28-year-old Kowar has a 2.08 ERA and 0.92 WHIP in seven appearances this season for the Mariners. He last pitched Saturday, striking out one in a clean inning to help Seattle in the second of three straight wins over Cleveland. He had allowed a run in each of his previous two outings.

Kowar, who was acquired in 2024 in a trade with Atlanta, made his M’s debut on May 28 after missing all of last season due to Tommy John surgery.

Mariners Radio Network coverage of Monday’s game on Seattle Sports will begin at 5:30 p.m. with the pregame show.

Here’s the Mariners’ lineup for the series opener against Boston:

WALTER’S BACK. #TridentsUp pic.twitter.com/mg3TQY7fZK

— Seattle Mariners (@Mariners) June 16, 2025

More on the Seattle Mariners

• 2025 may be the new career year for Mariners’ J.P. Crawford
• Mariners Observations: What stood out from sweep of Guardians
• Logan Gilbert’s Seattle Mariners return is set
• Touted Mariners prospect sidelined with another injury
• Jon Morosi: Two Seattle Mariners trade targets from AL West rival

Related

Scherzer, Blue Jays blank Mariners 7-0 to sweep seriesRed Sox get two key returns ahead of series against MarinersMariners place Emerson Hancock on the 15-day ILEx-Mariners OF Kelenic signs minor league deal with YankeesMariners fall to Blue Jays 4-3 in Kade Anderson’s 2nd startMariners Notebook: The latest on Hancock and Donovan