BALTIMORE -- Baltimore Orioles pitcher Jake Arrieta is scheduled to have season-ending surgery Friday to remove a bone spur from his right elbow.

Arrieta hasn't pitched since July 31 and has been on the disabled list since Aug. 6. The right-hander went 10-8 with a 5.05 ERA in 22 games, all of them starts. He's 16-14 in two seasons with Baltimore.

Arrieta was 5-1 with a 4.03 ERA on May 15 but began to struggle with his command shortly after that and went more than five innings in only one of his final seven starts. He issued six walks to the New York Yankees in his final outing.

Orioles manager Buck Showalter says he's looking forward to "Jake taking care of something that was a challenge for him as the year wore on."