Brisbane Lions coach Michael Voss is optimistic his side will regain the services of injured stars Josh Drummond and Jed Adcock for Friday night's knockout semi-final against the Western Bulldogs.

Voss, who sweated over the fitness of four key players last week, said Wednesday would be the ultimate deadline for Drummond to prove he had overcome a quad injury.

"It's one of those ones where he has to be able to train on Wednesday night - so we'll know after Wednesday if he's got any chance at all," Voss said on Monday.

"If he's right we'll name him, if he's not then we won't."

"At this stage I'm very hopeful he might be alright - much more hopeful than I was last week."

"But again with a quad, it's very unpredictable. It's hard to sit and say - (he's) absolutely in - because it can progress really well and all of a sudden it can take a turn for the worse."

Drummond was a late scratching from the side that triumphed over Carlton on the weekend after being initially named to take on the Blues, while Adcock has missed the last eight weeks with a knee injury.

Adcock's hopes of making an earlier than expected return were hampered due to the fact the Lions reserves were not a part of last weekend's QAFL finals, but Voss said his vice-captain was in the mix.

"He's a good chance, trained last week, will train today - so he's another one that will be a very good chance to play," he said.

"He would be (an enormous inclusion), because of the x-factors you talk about…the leadership and things like that."

"Jed's certainly fit, he's trained and he's fit enough to do that, but whether that means that he'll come in direct for a final - we'll make that decision later in the week."

Voss admitted he took a 'calculated risk' carrying in-doubt trio Simon Black, Daniel Bradshaw and Daniel Merrett into last weekend's elimination final, but said all three had made it through unscathed and would be right to take on the Dogs.

Voss was quick to pour cold water on reports skipper Jonathan Brown would be unable to fly to Melbourne for the semi-final due to the damage sustained to his eye socket in a nasty collision with Carlton's Heath Scotland.

"Browny is fine, he got stitches in his eye, but he'll play this week."

"I'm sure he's got a sore head, I'm sure his eye