"He's done," Detroit coach Mike Babcock said during the postgame news conference. An NHL source confirmed to ESPN.com that DeKeyser suffered a broken thumb.
It's a huge loss for the Red Wings, who had leaned heavily on the smooth-skating rookie since he signed with them in late March after finishing his season at Western Michigan University.
He played nearly 20 minutes in making his playoff debut in Game 1 and followed it up with another 16:15 in Game 2, before the injury cut his game short. The Red Wings have depth on defense, and can turn to a group that includes veterans Ian White and Carlo Colaiacovo and rookie Brian Lashoff for Game 3 on Saturday in Detroit.