Manager John Russell was hesitant to say whether the injury affected Dumatrait in his two previous starts in Baltimore and Chicago, where the southpaw surrendered 14 runs in 10 innings. The move, retroactive to Friday, will allow Dumatrait to come back as early as July 5, when the Pirates travel to Milwaukee.
Right-handed reliever T.J. Beam, who was selected from Triple-A Indianapolis, will take Dumatrait's place on the 25-man roster. And to make room for Beam on the 40-man roster, the Pirates transferred center fielder Chris Duffy from the 15-day DL to the 60-day DL.
"He'd been a little achy the last few weeks," Russell said of Dumatrait. "We've been able to keep it kind of under control. It's flaring up a little bit more, so just to be on the cautious side, we don't want this to linger. With the off-day [on Monday] and everything, we felt this was a good time to do it."
Dumatrait was scheduled to make his next start on Wednesday against the Yankees. The Pirates moved lefties Zach Duke and Paul Maholm up a day to fill in the rotation. Sunday's starter Ian Snell is now the probable pitcher for the Pirates on Friday, leaving Saturday's start open.
Russell said the decision on Saturday's starter is forthcoming. General manager Neal Huntington, though, said Triple-A right-hander John Van Benschoten is the most likely candidate to make the start.
As for Beam, this is the 27-year-old's second stint in the Major Leagues. He made a previous big league appearance with the Yankees in 2006, when he posted a 2-0 record and a 8.50 ERA in 18 innings. He spent the entire 2007 season with the Yankees' Triple-A affiliate Scranton/Wilkes-Barre.
This season, Beam, who signed with the Pirates on Dec. 22 as a Minor League free agent, became the Indianapolis Indians' most reliable reliever with a 2-1 record, 2.03 ERA, four saves, 39 strikeouts and .201 batting average against.
"We're excited to have him," Russell said. "He gives us some more depth in our bullpen. He's got the kind of arm I think we can use him in different areas in the bullpen."
Beam brings with him a fastball that can reach the mid 90s, a slider and a split-changeup combination. Russell plans to use the right-hander in sixth- and seventh-inning situations.
Because of Beam's quick arrival, the Pirates played Sunday's game without their traditional Sunday pinstripes. Only the home white jersey was available to Beam, which could be a cause for concern. The Pirates own a perfect 7-0 record when wearing pinstripes.
In other injury news, Russell noted that catcher Ryan Doumit caught a side pitching session on Sunday morning and everything checked out as normal. Doumit should be available to pinch-hit on Sunday, Russell said.
The Pirates also plan on giving Doumit extra work on Monday. If everything goes accordingly, Doumit should be able to play on Tuesday.
Right fielder Xavier Nady is also day-to-day. Nady, who has been out with a left shoulder injury, will take batting practice on Sunday. He will be given Monday off, and his status for Tuesday is still unknown.
Todd Krise is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.