In addition, the Canadiens announced that forwards Ryan White and Brandon Prust each have an upper-body injury and will miss Game 5 of the team's Eastern Conference Quarterfinal series against the Ottawa Senators on Thursday (7 p.m. ET, CNBC, CBC, RDS).
Goaltender Carey Price, who sat out overtime in Game 4 on Tuesday, is day-to-day with a lower-body injury and will be re-evaluated Thursday.
Price appeared to sustain his injury in the final seconds of regulation in Game 4. He made 30 saves, but when he reached for a high shot, he fell forward and stayed down for a moment. He was able to skate off under his own power, but when overtime began, Peter Budaj was in net.
This is the second year in a row Gionta has torn his biceps muscle; he underwent surgery Jan 11, 2012 to fix a torn right biceps muscle.
Canadiens coach Michel Therrien said Gionta took the latest injury news very hard.
"When he heard the news," Therrien said, "our captain was crying in my arms."
Gionta said, "It's discouraging. The fact that not too many people have had it and it happens in back-to-back years, it’s definitely hard to deal with."
Gionta had his left arm wrenched back in Game 1 of the series last Thursday. Gionta missed Game 2, played 18:10 in Game 3 on Sunday and collected an assist, then missed the 3-2 overtime loss in Game 4 on Tuesday.
Gionta said it was not so much a question of pain tolerance or doing further damage to the injury than it was his ability to use his left arm.
"It was uncomfortable and it's basically loss of certain function," he said. 'What we had to do to play, to support the elbow, wasn't something that we could do continually."
Gionta was tied for third on the Canadiens in the regular season with 14 goals in 48 games and his 26 points were ninth-best on the club.
Prust had one shot on goal and two penalty minutes in 15:48 of ice time in Game 4, a 3-2 overtime loss that left the Canadiens down 3-1 in the best-of-7 series.
White, who has one goal in three games, missed Game 4 due to injury.
The Canadiens also had some good injury news Wednesday: Center Lars Eller skated briefly in the morning with a trainer. Eller sustained a concussion and facial fractures when he was hit by Senators defenseman Eric Gryba in Game 1. Gryba received a two-game suspension from the NHL for the hit.
Though Therrien said there still is no timeline for a possible return, it gave the team a lift to see Eller back in the picture.
"It's great news to see him on the ice, to see him around the team, because this is a kid that everybody likes," Therrien said. "He's a good kid and we're all really upset with what happened to him. But to see him around the team means a lot to the players, to the coaching staff and everyone involved with the team. So that's great news."