Ottawa Senators captain Daniel Alfredsson, who suffered a concussion on Saturday in Game 2 of the opening-round playoff series against the New York Rangers, suffered a setback after Monday's morning skate, coach Paul MacLean confirmed on Tuesday. The 39-year-old veteran sat out Monday's match -- a 1-0 shutout loss to the Rangers -- and doesn't look as if he will be available for Wednesday's Game 4.