The Rangers announced the injury Thursday, less than 24 hours after Callahan scored his third goal in his past two games and appeared to be finding his scoring touch after going without a point in his first three games of the season. He missed the Rangers' season-opener recovering from offseason shoulder surgery.
Callahan finished third on the Rangers in goals (16) and fourth in points (31) last season. He led the team with six power-play goals.
With Callahan out, the Rangers on Thursday recalled forward Darroll Powe from their American Hockey League affiliate in Hartford. They also called up goaltender Jason Missiaen and sent goalie Cam Talbot to the Wolf Pack. The Rangers' next game is Saturday night against the New Jersey Devils in Newark, N.J.
The Rangers, now 2-4-0 after beating Washington, also are playing without forward Rick Nash, who has missed three games since taking an elbow to the head last Tuesday against the San Jose Sharks, and speedy forward Carl Hagelin, who is on long-term injured reserve following offseason shoulder surgery. Hagelin must sit out at least four more games before he's eligible to play.