GEELONG will give "brutal" skipper Joel Selwood every chance to prove his fitness from Sunday's concussion ahead of Saturday night's clash with Greater Western Sydney, teammate Patrick Dangerfield says.

Selwood was knocked out in the first 45 seconds of the Cats' two-point win over Fremantle when he clashed heads with Hayden Ballantyne.

He was stunned by the contact and looked likely to need the stretcher, but when it arrived, he shrugged it away to stand and walk off the ground.

He even broke into a jog as he neared the boundary and headed into the rooms for treatment.

Dangerfield said a decision on the captain's availability for the tantalising clash with the ladder leaders would be made much closer to the game.

"He won't play if he is not right, but I am confident we've got plenty of time before that decision needs to be made, and if he is right he will put his hand up," Dangerfield said on Monday.

"After the game, he was showing the young Auskicker of the Year through the clubrooms, so that shows you a bit about the skipper and what a special person he is.

"We'll make sure he goes through all the proper protocols from our medical department."

Dangerfield said it was "pretty concerning" to see the brave midfielder floored so dramatically and to take so long to regain movement.

However, he applauded the courage of the five-time All Australian after the bone-crunching collision he described as simply "part of the game".   

"I'm not sure I have seen a tougher player play the game. He is absolutely brutal, he sets a wonderful example for the team," Dangerfield said.

"It's great to play with him.

"It was really quite alarming early on, and it was wonderful to see him stand up and then be able to run off the field.

"It's something that it is a really dangerous part of our game, we all understand it is part of the game, contact is part of the game, but we were certainly concerned for him at the time."

The Cats medical staff will be busy this week with Tom Stewart (facial fracture), Darcy Lang (leg) and Lachie Henderson (groin) in the wars, while Scott Selwood had his hamstring worked on throughout the win over the Dockers.

Stewart went to hospital and won't play this week, but Lang is considered a chance after he ran into Lachie Neale in the third quarter and hobbled off.

Henderson also faces a fitness test after he was withdrawn from the squad on Friday.