"I'd be surprised if he's not down for a while," manager Joe Girardi said.
Capuano had been projected to serve as the Yanks' No. 4 or No. 5 starter after signing a one-year, $5 million deal with the club. The 36-year-old was 3-4 with a 4.35 ERA in 40 appearances (12 starts) last year for the Red Sox and Yankees.
The injury opens the door for another candidate to begin the year in the rotation, though the Yankees have already been entertaining multiple starting pitchers because they had been considering using a sixth starter at times in April and May.
With Capuano's projected return date unknown at this time, Girardi mentioned Adam Warren, Esmil Rogers, Bryan Mitchell and non-roster invitee Scott Baker as part of the group that will continue to make Grapefruit League starts. Chase Whitley has also started this spring.
"We [will] look at everyone. That's the bottom line, because we need to fill a spot now," Girardi said.
General manager Brian Cashman said earlier on Wednesday that he has been particularly impressed by the 29-year-old Rogers, who posted a 4.68 ERA in 18 games (one start) for the Yankees in the final two months of last season after being claimed off waivers from the Blue Jays.
"[Pitching coach] Larry [Rothschild] worked with him long and hard last year during some bullpen sessions about changing a few things," Girardi said. "I thought he pitched pretty well for us. He's started in his career and he's got a number of pitches he can go to. He's been really good this spring. He'll be one of the guys we're really looking at."
Bryan Hoch is a reporter for MLB.com. Follow him on Twitter @bryanhoch and read his MLBlog, Bombers Beat. This story was not subject to the approval of Major League Baseball or its clubs.