Toronto Blue Jays closer Ken Giles will have Tommy John surgery on his right elbow, likely causing him to miss all of 2021 and impacting the deal he will receive as a free agent this offseason.

A right-hander who turned 30 on Sunday, Giles is 0-0 with a 9.82 ERA and one save in four appearances this season. He left a July 26 game at Tampa Bay because of forearm soreness and was placed on the injured list the next day. He returned with one inning against the New York Mets on Sept. 11, pitched one inning at the New York Yankees on Sept. 15, then went back on the injured list the following day.

Manager Charlie Montoyo said Giles decided Monday to go ahead with the surgery.

“He was a great clubhouse leader. He was awesome. I love the guy,? Montoyo said. “When he was on the mound, when he was healthy, he was one of the best relievers in baseball.”

Giles earned $3,555,556 as a prorated share of his $9.6 million salary this season.

He was 2-3 with a 1.87 ERA in 53 games last year, saving 23 games in 24 chances. He was on the injured list because of elbow soreness in June 2019 and pitched in three straight games from July 2-4 but did not appear in consecutive games again the rest of the season.

A seven-year veteran who has also pitched for Philadelphia and Houston, Giles has a 14-18 record with a 2.47 ERA and 115 saves in 130 chances over 357 big league games.

Toronto acquired Giles from Houston at the trade deadline in 2018, sending Roberto Osuna to the Astros after Osuna was suspended for 75 games under baseball’s domestic violence policy. Giles had lost the closer’s job with Houston after he punched himself in the face that May 1 while heading to the dugout after giving up a three-run, ninth-inning homer to the Yankees’ Gary Sanchez.

Also Monday, the Blue Jays activated right-hander Matt Shoemaker (shoulder) off the injured list to start against the visiting Yankees. Right-hander Julian Merryweather (right elbow) was placed on the 10-day injured list, retroactive to Sept. 18.