NEW YORK – Mike Richter is out for the season and the New York Rangers didn’t miss a beat in acquiring goaltender Mike Dunham to replace him.

Richter hasn’t played since a concussion on Nov. 5, and it was determined Thursday night that he would not play again this season. At the time of that announcement, the Rangers traded with the Nashville Predators to get Dunham.

General manager Glen Sather said he was exploring deals the past 10 days as Richter was slow to recover from being kneed in the head against the Edmonton Oilers.

“I anticipated getting better from the moment I got hit,” Richter said. “I didn’t even expect to miss a practice.”

Dunham played college hockey at the University of Maine from 1990-93. He was sent to New York for forward Rem Murray, defenseman Tomas Kloucek and the rights to defenseman Marek Zidlicky. The Rangers have started 19-year-old Dan Blackburn in all 17 games without Richter.

Sather didn’t say who would take Richter’s place as the Rangers’ top goalie. He’s just looking for someone to help them better a 12-15-4-1 mark.

“Mike has been a No. 1 goaltender,” Sather said. “I suppose it depends how things shake out with him and Danny. I’m more concerned with winning games than who will be No. 1 or No. 2.

“I didn’t want to see Danny lose his confidence and struggle and have our team struggle.”

The determination that Richter was lost for the final 50 games led Sather to pull the trigger on the trade.

“I thought Dan has played very well. He looked liked he was starting to get tired,” Sather said. “To expect him to be the goaltender for the next 50 games wouldn’t be fair to him or fair to us so we had to make a deal.”

In a separate trade, the injury-riddled Rangers also acquired forward Josh Green from Edmonton for a conditional pick in the 2004 draft.

The 36-year-old Richter, the winningest goalie in Rangers history, has battled significant injuries each of the last four seasons. In 2000, he needed reconstructive surgery on his left knee. The following season, he sustained a similar injury to his right knee.

He missed the latter part of last season after he was struck by a shot that caused a skull fracture and a concussion.

Richter saw two concussion specialists this week – Dr. Karen Johnston in Montreal on Monday and Dr. James Kelly in Chicago on Tuesday. Both recommended he not play again this season, and the final determination to sit out was made Thursday after Richter spoke with Johnston by telephone.