Brownlow Medallist Lachie Neale will have surgery on a syndesmosis injury and miss up to eight weeks of the AFL season.
The Brisbane star hurt his right ankle in a contest during Saturday night's win over Carlton at Marvel Stadium.
As the Lions had already used their substitute - with Tom Berry replacing the concussed Darcy Gardiner - Neale played through duress and still collected 24 disposals and six clearances in the 18-point victory.
"What Lachie did on the weekend for our football club was huge,'" Lions football manager Danny Daly said.
"That was an important game, we had already been forced to make an injury substitution and he stayed out there and battled on under duress and played a huge part in helping us get the win.
"This setback is unfortunate for Lachie but he is the complete professional and we know that he will do everything in his power to get back as quickly as possible, and we are confident he will play more great footy for us this year."
Losing Neale is a huge blow for Brisbane, who have won their past two games to sit 3-3.
The 27-year-old had been below his stunning best this season, with a niggling back injury hindering his performances earlier in the year.
Neale was fined for contact with an umpire during the win over the Blues.