Bolton (illness) was activated from the 15-day injured list and will serve as the 27th man for Sunday's doubleheader at Colorado.

Bolton (illness) fired a scoreless relief inning in Triple-A Tacoma's loss to Las Vegas on Thursday, issuing a walk and recording two strikeouts.

Mariners manager Scott Servais revealed Monday that Bolton was placed on the team's 15-day injured list due to kidney stones, Ryan Divish of The Seattle Times reports.

Bolton was placed on the 15-day injured list by the Mariners on Monday, retroactive to April 6, with a general medical issue, Ryan Divish of The Seattle Times reports.

Bolton fired 1.2 scoreless, hitless relief innings during which he recorded two strikeouts in a loss to the Guardians on Tuesday.

Bolton (ankle) struck out one over a perfect inning of relief Friday in the Mariners' 9-5 loss to the Cubs in Cactus League play.

Mariners manager Scott Servais said Wednesday that Bolton recently experienced some discomfort in his ankle and had his throwing schedule adjusted as a result, Ryan Divish of The Seattle Times reports.

Seattle acquired Bolton from the Pirates on Thursday in exchange for cash considerations.

The Pirates recalled Bolton from Triple-A Indianapolis on Friday, Justice delos Santos of MLB.com reports.

Bolton was optioned to Triple-A Indianapolis on Wednesday.