Stastny was injured while blocking a shot at Minnesota on March 17 and will be out two to four weeks, the team said Wednesday. Team doctor Andrew Parker said a CT scan revealed the fracture on Tuesday.
The Avalanche are at the bottom of the Western Conference standings and mired in the worst season since the franchise moved from Quebec to Denver in 1995. They play their final regular-season game on April 12.
Stastny is fourth on the Avalanche with 36 points in just 45 games. He missed 26 games earlier this season with a broken forearm.
The Avalanche recalled forward Matt Hendricks from Lake Erie of the American Hockey League.