Thomas was hurt in the third period of the Panthers' game Tuesday against the Chicago Blackhawks. With 2:59 remaining in regulation of a 2-2 game, Thomas went down to make a save and stayed on the ice in obvious discomfort. After the next whistle he skated to the Florida bench and then left the ice. He was replaced by Jacob Markstrom in what ended as a 3-2 Blackhawks shootout victory.
It was Thomas' third straight start after missing four games with a groin injury sustained during a 2-1 loss to the Philadelphia Flyers on Oct. 8.
It's likely veteran Scott Clemmensen will be called up from the club's American Hockey League affiliate, the San Antonio Rampage, to split time in net with Markstrom.
Thomas returned to the NHL this fall at age 39 after sitting out last season and is 2-3-0 with a 3.11 goals-against average and .905 save percentage in six games.