But coach Peter Horachek does not anticipate an extended absence for his young defenseman.
"He should be OK," Horachek said, adding Gudbranson will not go on injured reserve.
Gudbranson played his final shift of the first period with 1:04 to play then remained in the dressing room after the first intermission.
It was not immediately clear what happened to Gudbranson, but just before leaving the ice on his final shift, he was engaged in a puck battle in the corner of the Panthers defensive zone with Canadiens forwards Max Pacioretty and David Desharnais. He skated slowly to the bench once the Panthers succeeded in clearing the puck.
The injury forced the Panthers to go with five defensemen for the final 40 minutes of the game. Brian Campbell playing a game-high 31:17, marking the third straight game he topped the 30-minute mark, though the previous two went to a shootout. Dmitry Kulikov played 24:17 and Mike Weaver played 21:35 for the shorthanded Panthers.
"Playing with five guys from early on in the game is a tough thing, in any building," Horachek said. "Campbell was probably out every other shift and so was [Kulikov] and Weaver. It shows that they played with a purpose and resolve."
Gudbranson entered the game fourth on the Panthers in average ice time at 19:15 per game, including 2:08 per game on the penalty kill and 1:17 per game on the power play. He is one of six Panthers to have played in all 34 of their games this season.
The Panthers were already shorthanded up front with Jonathan Huberdeau missing the game due to a foot injury. He was wearing a walking boot on his right foot, but said he hoped to play in Florida's next game on the road against the Toronto Maple Leafs on Tuesday.