Oft-injured Rick DiPietro is out of the New York Islanders' lineup again, this time after he was hurt in practice.

DiPietro, who served as the backup to goalie Al Montoya in New York's first two regular-season games, was scratched Thursday night — one day after he was struck in the mask by a shot fired by new teammate Brian Rolston.

Montoya started again Thursday against the Tampa Bay Lightning, with Evgeni Nabokov as the backup for the first time since he joined the Islanders.

DiPietro has a history of concussions in his injury-plagued career, and was being evaluated Thursday to see if he had another. The 30-year-old netminder, in the sixth season of a landmark 15-year contract with the Islanders, has played a total of 39 games in the past three seasons.

Islanders coach Jack Capuano was hopeful that DiPietro hadn't sustained another concussion.

"He said he felt pretty good," Capuano said. "I saw him when he had a concussion before and he looks much better now."

DiPietro missed the majority of the 2008-09 and 2009-10 seasons because of a knee injury and has also had surgery on both hips since being chosen No. 1 overall by the Islanders in the 2000 draft.

Last season, DiPietro was sidelined for several weeks because of broken bones in his face caused by a punch from Pittsburgh goalie Brent Johnson on Feb. 2. DiPietro was felled by a left hook above his right eye, and the broken bones and swelling in his knee kept him out of action until March 19. He played in five games after returning.

DiPietro played in a total of 13 games in the two previous seasons because of his troublesome knee. He has never played more than 63 games in a season.