Weiss will have the surgery next week, said Panthers general manager Dale Tallon.
"Not good news," Tallon said in Sunrise, Fla., after the Panthers completed a game-day morning skate. Florida was preparing to host Winnipeg at home later Tuesday night.
By any measure, the Panthers are losing both games and players at an alarming rate. Tallon began his remarks on Tuesday by updating the status of several injured players -- goaltender Jose Theodore, who is expected to miss up to six weeks with a leg injury among them.
Then he paused and broke the news about Weiss.
"This is the kicker," Tallon said.
Weiss will be a free agent after the season, meaning his 11-year run with Florida could be over. Weiss had only one goal and three assists in 17 games this season, clearly laboring at times.
"We saw a different player in the past," Panthers coach Kevin Dineen said. "It obviously affected his game. It's a loss for us."
The Panthers entered play Tuesday with the second-fewest points in the NHL standings, not at all what the reigning Southeast Division champions were hoping for entering the season. Through the season's first 22 games, the Panthers had been outscored by 27 goals, by far the worst goal-differential in the league.
Still, both Tallon and Dineen refused to give up on the season.
"You can't worry about the uncontrollables," Dineen said. "Until guys are back, we'll move forward. ... The players we have here understand what our situation is now. I think they're the right guys to find that step to get us in the right direction."
And as the Panthers try to take that step, a young goaltender will be the go-to guy. With Theodore out, Tallon said the Panthers will use Jacob Markstrom in the No. 1 role in the net.
Markstrom, who entered Tuesday with eight career starts in the Panthers' goal, has long been considered Florida's goalie of the future. Apparently, the future has arrived.
"I've got a lot of confidence in the young man," Tallon said. "We were hoping to hold off a little bit, but let's go, let's see if he can do it. And I believe he can."
Also hurting for Florida these days, besides Theodore and Weiss: Defensemen Dmitry Kulikov (upper-body) and Mike Weaver (lower-body) are expected to miss 3-4 weeks; Scottie Upshall and Ed Jovanovski could be out for up to 10 more days each, and forward Kris Versteeg may return to the lineup as early as Friday.
In addition to all those woes, Florida still does not have a final decision on the Alex Kovalev situation. Kovalev has been away from the team for several days, with the team saying he is weighing his options. Still, it would seem that Kovalev's days with the Panthers are likely over.
"It's ongoing discussions," Tallon said. "We'll have some finality to it, hopefully this week."
Also Tuesday, the Panthers recalled right wing Jon Rheault from their AHL affiliate in San Antonio. Rheault had 37 points in 50 games in the minors this season, and was set to make his NHL debut Tuesday night.
The Panthers entered Tuesday with just two wins in their last 12 games -- and in this lockout-shortened 48-game season, a slump like that will be particularly tough to overcome.
The injuries only add to the challenge.
"But that's part of hockey, part of this condensed season," Tallon said. "Everybody goes through it and it's an opportunity for others to show their worth. ... We'll find a way to get through this. It's all you can do.
"We still have a chance. Kevin and his staff are going to find a way, the players are going to find a way and I'm going to find a way to compete for a playoff spot. Regardless of what the situation is, we've got to deal with it."