WASHINGTON -- Stephen Strasburg is getting a different type of shutdown, a stint on the disabled list because of a strained muscle in his back.
The Washington Nationals placed their top-of-rotation pitcher on the 15-day DL on Wednesday after he was unable to make a scheduled bullpen session.
"There's still some tenderness and discomfort there," manager Davey Johnson said. "So we're going to keep him off the mound for a few more days."
Strasburg was removed after two innings in his last start, Friday against the Atlanta Braves, because he was grimacing and flexing his shoulder. He said after the game that his back had been bothering him while warming up for his previous few starts but would feel fine once the game started.
The Nationals said on Sunday that Strasburg has a "slight strain" to the lat muscle. Johnson was hoping the right-hander would not miss a start, although Strasburg's next turn in the rotation was moved back two days to Saturday.
After Strasburg played catch instead of throwing the bullpen session Wednesday, the Nationals put him on the DL, retroactive to Sunday.
Strasburg is 3-5 with a 2.54 ERA. He was 15-6 with a 3.16 ERA last season, when the Nationals made the much-debated decision to shut him down before the playoffs because of a team-imposed innings limit in his first full season following elbow surgery.
The Nationals now have two starters on the DL. Ross Detwiler has been sidelined since May 15 with a strained oblique muscle. He threw a bullpen session Wednesday and will make a rehab start in the minors before returning to the rotation.
Nate Karns has made his first two major league starts in Detwiler's place, and Johnson said the Nationals will promote another pitcher from Triple-A Syracuse to start in Strasburg's place on Saturday. A prime candidate is right-hander Ross Ohlendorf, who has pitched for three major league teams and is 4-5 with a 4.32 ERA at Syracuse.
The Strasburg news overshadowed a cosmetic change for Johnson: The manager arrived at the dugout clean-shaven for the first time in more than two weeks.
Johnson had been refusing to shave because of the Nationals' hitting woes, but he broke out the razor in the wake of his team's first late-inning come-from-behind win of the season. The 3-2 victory over the New York Mets on Tuesday was the first time in 2013 that Washington won when trailing after six innings.