ADELAIDE defender Nathan Bock has come through Tuesday's training session unscathed, increasing his chances of playing against Essendon on Friday night.

Bock, 26, hasn’t played since being diagnosed with a microfracture in his heel after the round 18 loss to Geelong.

Adelaide coach Neil Craig admitted he was unsure how Bock would fare when he made his AFL return.

“We know it’s difficult to come back [from an injury lay-off] in the minor round competition, let alone to come back when the best are playing the best. But hopefully that will be a decision we’re faced with at some stage,” Craig said on Tuesday.

“It can be one of the most difficult decisions to make because there’s a sense of urgency in terms of the result and sometimes that can cloud your thinking.

“I think we’ve all been around long enough to know that to play unfit players when the best are playing the best, you do it at your peril … there may be a situation where you have to do it, but do it at your peril.”

Injured duo Nathan van Berlo (back) and David Mackay (ankle) will sit out Tuesday’s main training session, but Craig said he expected both to be available for the clash with the Bombers.

“Nathan’s back has showed significant improvement from the weekend, so we’re very hopeful he’ll be okay. He won’t train fully tonight, but he’ll do a lot more tomorrow. He needs probably another day for that to settle down in the right manner,” Craig said.

Ruckman Brad Moran will also join in main training for the first time since rupturing the posterior cruciate ligament in his knee against the Sydney Swans back in June.

James Sellar has performed admirably as the second ruckman since Moran’s injury but Craig said he hadn’t ruled out recalling Moran or fellow big man Jon Griffin— who has had a suspected calf strain downgraded— during the finals series.

“Jon needs to continue to play in the SANFL and put performances on the table to push his case. I’m very open-minded about that part of our game,” he said.

“Brad Moran is a bit different. He’ll actually join in our full training session tonight, but he hasn’t played for eight or so weeks so that’s a big decision.

“He’s been very diligent in the way he’s rehabilitated and you just never know in this industry. His aim is to get himself fully fit and ready to play if required. It would be useful for him to be available.”