DiPietro fought with Penguins goalie Brent Johnson in the Feb. 2 game and was felled by a clean left to the right of his head. DiPietro ended up with facial fractures, which were discovered in tests the next day.
"It was tough to tell at the time," DiPietro said. "Your adrenaline is rushing so hard that fortunately in a fight like that you don't feel anything until afterward. It's unfortunate and frustrating and every other emotion you can throw in there."
DiPietro also suffered swelling in his oft-injured knee.
DiPietro played in a total of 13 games the previous two seasons because of his troublesome knee. He's also had operations on both hips and has a history of concussions, as well. He has never played more than 63 games in any of his nine NHL seasons, since the Islanders picked him No. 1 overall in the 2000 draft.
The Islanders are tied for the second-worst record in the Eastern Conference entering Wednesday night. DiPietro is 7-10-4 with a 3.36 goals-against average in 21 games.
Al Montoya has been starting for the Islanders, with a 7-3-3 record in 14 games and a 2.36 GAA.
ESPN.com's Pierre LeBrun contributed to this report.