Manager Joe Girardi said Tuesday that team doctors in New York were looking over an MRI Chamberlain had on Monday. He last pitched Friday and is on hold until further notice.
"Whenever a pitcher -- or anybody -- is dealing with an oblique, there's always concern," Girardi said. "He's been asymptomatic, but he hasn't thrown . . . It's one thing to feel OK, and it's another thing to go through the [pitching] motion and feel OK."
Sergio Mitre, who was scratched from his start Monday because of a similar injury, is ahead of Chamberlain, Girardi said. Mitre did not have an MRI, and the Yankees are hopeful he can throw a bullpen session tomorrow. Mitre missed more than five weeks last season with an oblique strain.
Both righthanders feel discomfort on the left side and received treatment Tuesday at Steinbrenner Field. Girardi said the Yankees would have to see Chamberlain throw a bullpen session before they put him in a game again, and there is no timetable for that.
"Joba said functionally he's fine," Girardi said. "But I think they might give him a couple extra days. They just want to go slow and make sure they're doing the right thing."
The Yankees were off Tuesday except for Bartolo Colon and CC Sabathia, who pitched to minor-leaguers in a simulated game. Sabathia allowed two hits in 61/3 simulated innings (82 pitches) against four rotating minor-leaguers. It was nothing more than a tuneup and a chance to pitch to Russell Martin.
For Colon, it was part audition, part tuneup. Girardi, pitching coach Larry Rothschild and general manager Brian Cashman were among those watching the 37-year-old righty throw 79 pitches in six simulated innings. Colon gave up four hits, struck out seven and appeared sharp.
"Great workday for both of them," Girardi said. "It was a good chance to really build them up. I thought [Colon's] location and his strikes were good. He threw some really, really good sliders. We know he has a great fastball and a great changeup, but that was one pitch he didn't throw a lot of back in the day."
Colon's next outing will come Monday as he continues to battle with Ivan Nova and Freddy Garcia for the final two spots in the rotation. Nova will pitch Wednesday night against Baltimore, and Garcia faces Toronto on Saturday.
The surprise has been Colon, who did not pitch in the majors in 2010. The Yankees signed the 2005 AL Cy Young winner after he performed well in winter ball for first-base coach Tony Peña.
"I had an opinion on Bartolo, but it was from years ago," Girardi said. "You kind of wanted to see what was there because we haven't seen him pitch in a while. I don't remember the last time I've really seen him pitch in a big-league game. But I've been pleasantly surprised."