Florida also announced it returned goaltender Jacob Markstrom and defenseman Alex Petrovic to the San Antonio Rampage of the American Hockey League.
Thomas suffered a groin injury during practice on Dec. 12 which kept him out of of action for six games. It marked the second time this season the lower-body injury plagued the two-time Vezina Trophy winner.
Markstrom appeared in one game since being called up following Thomas' injury. He allowed five goals on 32 shots in Florida's 5-2 loss to the Winnipeg Jets on Dec. 21.
Petrovic made his season debut in the Panthers 6-1 loss to the Tampa Bay Lightning Monday night. He logged 15:35 in ice time and led Florida with eight hits.
The Panthers return to practice Friday before hosting the Detroit Red Wings the following night.