SEATTLE -- After ending the season with eight players on the 60-day injured list, the Mariners have whittled that number down to three on Friday, when reliever Gerson Bautista was outrighted to Triple-A Tacoma and lefty Taylor Guilbeau was claimed off waivers by the D-backs.

But the Mariners added a newcomer to their bullpen mix by claiming right-hander Domingo Tapia off waivers from the Red Sox. Tapia is a 29-year-old who made his Major League debut in September and pitched in five games for Boston, allowing one run on four hits with four strikeouts in 4 1/3 innings while averaging 99 mph with his fastball, per Statcast.

The latest moves leave catcher Tom Murphy, outfielder Mitch Haniger and reliever Andres Muñoz as the only players that will need to be reinstated from the 60-day IL back onto the 40-man roster next week, a requirement within five days after the conclusion of the World Series.

The club had already outrighted injured relievers Carl Edwards Jr., Matt Magill and Nestor Cortesto to the Minors on Thursday, with all three electing to become free agents after clearing waivers.

Right-hander Art Warren, the Mariners’ No. 25 prospect, also didn’t clear waivers earlier this week, as he was claimed by the Rangers on Wednesday after spending the 2020 season at Seattle’s alternate training site.

The flurry of moves clears up 40-man roster openings for the Mariners, who are looking to add three or four experienced relievers this offseason via either free agency or trade as general manager Jerry Dipoto seeks to upgrade a bullpen that had the worst ERA in the American League last season at 5.92.

The 40-man roster is at 34 following Tapia’s acquisition, though Murphy, Haniger and Muñoz will need to be added and several prospects will presumably be promoted to protect them from the Rule 5 Draft in the coming weeks.

Tapia, a 6-foot-3, 263-pound right-hander, spent all of 2019 with Triple-A Pawtucket, where he went 5-4 with two saves and a 5.18 ERA (38 ER, 66.0 IP) in 44 games (1 start).

Tapia was originally signed as an international free agent in 2010 by the Mets and has spent 10 seasons in the Minors with the Mets, Reds and Red Sox, compiling a 38-50 record and 4.14 ERA in 242 games (102 starts).

Guilbeau, a 27-year-old lefty, posted a 2.70 ERA in 25 appearances with the Mariners after he was acquired from the Nationals at the July 31 Trade Deadline in 2019. He had a 1.17 ERA in 7 2/3 innings over eight outings this season, with three strikeouts and six walks, before going on the injured list on Aug. 21 with a strained left shoulder.

Bautista, 25, is a right-hander who opened eyes with his electric arm the past two Spring Trainings but ran into injury issues both years. He pitched eight games for Seattle in 2019 after returning from a strained right pectoral muscle but allowed 11 runs on 13 hits and nine walks over nine innings.

Bautista spent all of the 2020 season on the injured list with a right elbow sprain that occurred in July after the club opened Summer Camp following the three-month shutdown.