Powe was helped off the ice after a frightening collision with Washington's Matt Hendricks early in the second period of the Rangers' 2-1 win against the Capitals on Sunday.
"I missed him right away on the bench, especially protecting a lead," Tortorella said. "I don't know how long he's going to be out. He doesn't have the stats, but it's not always about the stats. He's done a lot of good things in his role."
Powe was said to be feeling better a day after the collision. He appeared to be unconscious after the hit and was down on the ice for several minutes looking dazed, and the team is handling the injury with caution.
Down one of their best penalty killers, the Rangers recalled physical forward Brandon Mashinter from the team's AHL club, the Connecticut Whale. It is not yet clear whether Mashinter will make his debut or whether Chris Kreider will play in place of Powe in Tuesday's game against Montreal.
"I've been interested to look at Mashinter. He's an interesting one to me, but I'm not sure," Tortorella said. "I'm not sure what the lineup's going to be. A number of things come into play."
Both skaters practiced with the team Monday.
Mashinter, 24, has five goals and six assists in 14 games this season for the Whale. He previously played 13 NHL games for the San Jose Sharks in 2010-11.