The Pittsburgh Pirates have put right-hander Stolmy Pimentel on the 15-day disabled list because of a sprained right ankle and activated Canadian reliever John Axford.
The Pirates made the moves before Friday night's game at Washington.
Pittsburgh claimed Axford off waivers Thursday from the Cleveland Indians. The 31-year-old Ancaster, Ont., resident was 2-3 with 10 saves and a 3.92 earned-run average in 49 games this season for the Indians.
For his career, Axford is 24-22 with 116 saves and a 3.38 ERA. He had 46 saves for the National League Central champion Milwaukee Brewers in 2011.
The 24-year-old Pimentel is 2-1 with a 5.40 ERA in 19 relief appearances this season.
Pittsburgh second baseman Neil Walker, who has missed 11 of the last 12 games with back tightness, was in Friday night's starting
"The muscle spasm is completely gone," Walker said before the game. "So we're in a pretty good place right now."