Wells has missed the Roos' past two games after a teammate landed on his foot at training before the round five clash against Collingwood.
Despite having last week's bye to recover, Wells was still restricted to light ball work when the Roos' main group trained at Arden Street on Wednesday.
North coach Brad Scott told reporters before training that the Roos had still not been able to pinpoint the exact nature of Wells' injury, but were confident the midfielder had suffered nothing more serious than bone bruising.
"He's much better than he was this time last week," Scott said of Wells.
"If we had a game last week he wouldn't have played in that.
"You'd have to say he's still in some doubt but we'll train today and see how he pulls up.
"But he's missed enough footy now to suggest that he needs some training under his belt, so he'll have to train pretty well."
PRESS PLAY above to watch the Brad Scott media conference | YouTube
In better news for North, Scott said skipper Andrew Swallow remained on track to return this Saturday from the ruptured left Achilles tendon that has sidelined him since round 18 last year.
But the coach said the Roos were unlikely to ease Swallow back into senior football in the substitute's green vest.
"He trained really strongly on Monday, he'll train again today and if he trains well we'll select him," Scott said.
"He's our captain and even though Chris Judd [returned from injury as Carlton's substitute] I tend to think if we pick him we'll pick him to play a full game."
Scott signaled room for change after North's disappointing round seven loss to Gold Coast, with Ben Jacobs, Robbie Nahas, Liam Anthony, Sam Wright and Scott McMahon all in line for a recall to face the Lions.
Scott said North's coaching team had conducted a thorough review of the Gold Coast loss and their entire season to date during the club's bye last week.
"I think that areas of our game that we really needed to address (from last year), particularly the defensive aspect of our game (and) absorbing momentum, have clearly improved," he said.
"But in improving that part of our game we've dropped off in the offensive part of our game.
"So the balance is the key that we're looking for."
