Tapia (biceps) was claimed off waivers by the Mariners on Friday.
The 29-year-old was designated for assignment by the Red Sox, and the Mariners didn't allow him to pass by on the waiver wire. Tapia made his big-league debut in 2020 and gave up one run on four hits with four strikeouts and two walks over 4.1 innings before landing on the injured list with a right biceps contusion. Barring a setback, the right-hander shouldn't have any issues being ready for the start of spring training in February.