Ryan Callahan of Lightning to miss four weeks

Tampa Bay Lightning forward Ryan Callahan is expected to miss approximately four weeks with a lower-body injury.
Callahan was injured in a 4-2 loss at the Philadelphia Flyers on Jan. 7 and has missed the past three games. He previously missed 15 games with a lower-body injury before returning against the Winnipeg Jets on Jan. 3.

The 31-year-old has two goals and two assists in 18 games this season.
Lightning coach Jon Cooper said he was worried about Callahan's condition before Tampa Bay's game against the Columbus Blue Jackets on Friday.
"There's lots of concern," Cooper said. " ... Let's move our team aside. It's Callahan. Everybody knows who follows our team what a gamer he is, his passion to play and to help our team, especially when things haven't gone as well as we'd have hoped. For him to get in for [three] games and have to be out with some lingering effects with some past issues he's had, it's killing the kid.
"So you feel for him. We're missing an emotional leader. It's tough all the way around."