Updated

Islanders rookie goalie Kevin Poulin will miss the rest of the season after hurting his knee during pregame warmups.

Poulin caught his skate in a rut in the crease and fell awkwardly Tuesday night moments before the opening faceoff against the Toronto Maple Leafs.

An MRI on Wednesday revealed a dislocated left knee cap that will require surgery and end the season for the 20-year-old Poulin.

The injury forced the Islanders to start Mikko Koskinen in his NHL debut, a 5-3 loss to the Maple Leafs.

New York didn't have a backup goalie on the bench until the third period, when Joel Martin made it to Long Island from Bridgeport of the AHL.

New York, which is already missing goalies Rick DiPietro (face, knee) and Nathan Lawson (knee), acquired Al Montoya from the Phoenix Coyotes on Wednesday for a sixth-round pick in this year's draft.

Montoya, the No. 6 overall pick in the 2004 draft by the New York Rangers, was assigned to Bridgeport. He was 11-8 with a 3.19 goals-against average in 21 games this season for San Antonio of the AHL.

In other moves Wednesday, the Islanders said that center Jeremy Colliton will be out for two weeks because of a rib injury sustained in Tuesday's game. New York also placed DiPietro on the injured list and recalled forward Jesse Joensuu from Bridgeport.

DiPietro is expected to be out for four to six weeks because of injuries he sustained in a one-punch fight with Pittsburgh goalie Brent Johnson last week and recurring swelling in his surgically repaired left knee.

In September 2007, the oft-injured DiPietro fought Montoya in a preseason game between the Islanders and Rangers.