Cowen underwent surgery in November to repair a torn labrum in his left hip after being injured in an American Hockey League game, and the thinking at the time was he would be lost for the remainder of the season.
It's a huge boost for an Ottawa team that is without Erik Karlsson (Achilles) on its blue line.
"It's a big day," Cowen said. "I've had this day in mind for a while. I picked it a long time ago because it's not a back-to-back and it's at home. I wanted to start at home. I worked really hard to get here. Sometimes rehab doesn't go the way you want it to. A lot of it has been luck. When I'm on the ice doing drills or skating, I don't think about my hip at all, and my doctor said that's the key. All systems are go."
Cowen played in all 82 games for the Senators as a rookie last season, posting five goals and 17 points. The 22-year-old was a first-round pick (No. 9) in the 2009 NHL Draft.
Here are the projected lineups for the Hurricanes and Senators: