Doctor Peter Larkins has backed Geelong star Steve Johnson to line up on Friday night despite injury concerns.

The respected medical expert and commentator told AFL.com.au Johnson had pulled up ‘quite well’ and believes the Cats will risk him.

“He's still got the stress injury and ideally he'd have more time off, but I think Geelong will play him on Friday night, knowing that if the bone fully breaks it's campaign over for Stevie.

Larkins though, warned the dice roll could backfire.

“The chances of him breaking the foot are minor, but they are real. I suspect Geelong will modify his training this week so he doesn't risk putting too much load through his foot and I think he's practically 100 per cent sure to play against North Melbourne.”

Geelong is also nursing Steven Motlop’s shin soreness Jordan Murdoch’s hamstring tightness and James Kelly’s calf but Larkins says they’re all likely to run out after some intense physiotherapy and massage.

“Even though he completed last Friday night's game, the Cats will be looking to extend Murdoch at training later in the week to make sure he hasn't got a minor hamstring injury. If he completes training, he should be available for selection.”

Allen Christensen hasn’t played since Round 22 with a back issue and won’t return to face the Kangaroos.

“The Cats are expecting to rest him again this weekend in the hope that they make the preliminary final against the Sydney Swans next week. If the Cats can beat North, Christensen should be available to take on the Swans.