Martin sparked speculation he was under an injury cloud with his early departure from a training session at Punt Road, just a week out from Friday night's blockbuster encounter with the Magpies at the MCG.

Club officials initially insisted Martin was fine but coach Damien Hardwick told reporters on Wednesday that a knock suffered in the qualifying final win against Hawthorn had limited his preparation.

"It's a pretty significant corkie with bleeding down into his knee," Hardwick said.

"That takes a little bit of time to settle but it's settled now and he'll be available to play on Friday.

"... He's battled through these sort of things before and we've had the week off, so we're not in any rush to get him out to train to make sure that he plays.

"We've just taken a conservative approach.

"The reality is he's not going to get any fitter, stronger or better now ... all we've got to do is get him to the line and make sure that he plays."

Collingwood defender Jeremy Howe was sidelined for several weeks with a corked thigh late in the season and was forced to undergo a procedure to drain excess blood.

Hardwick said that could have been a consideration for Martin but there wasn't enough blood to warrant it.

He is confident last year's Brownlow Medal winner will be between 95 and 100 per cent fit when he takes the field against the Pies.

"The injury is not that significant that it will change his role," Hardwick said.

"The way Dustin's role pans out on game day is probably dependant on the opposition.

"At various stages we'll need him on the ball and at various stages we'll need him up forward."

Hardwick also revealed small forward Dan Butler is in the selection mix after overcoming an ankle injury.

Australian Associated Press