Callahan left the ice seconds after initiating contact in the offensive-zone corner with Nashville defenseman Victor Bartley during his fourth shift of the night. He did not return, and the Rangers announced after the game that Callahan suffered a Grade 2 sprain of his medial collateral ligament.
"It's been a tough stretch for him and we all feel for him," defenseman Dan Girardi said. "Everyone has to step up a little more. He brings a lot to the team, a lot of different characteristics. And someone's going to have to find a way to step up for him. Everyone's got to be better, for sure."
Callahan has seven goals and 13 points in 24 games this season. He missed the season-opener following offseason shoulder surgery and later sat out seven games with a broken thumb.