NORTH Melbourne coach Brad Scott says he is "cautiously optimistic" forward Leigh Adams will return to the Kangaroos after suffering yet another concussion last month.

Adams, 27, was knocked out after receiving a head knock while playing for VFL affiliate Werribee in a practice match against Footscray.

There had been speculation the 104-gamer had been contemplating retiring from the game following a spate of heavy knocks, including one in round 23 last season that sidelined him from North's three finals.

But Scott said he is confident Adams will return, provided he passed the relevant testing next month.

"He's progressing really well. We've taken a very cautious approach with him and he'll go through a battery of tests over the next couple of weeks," Scott told Fox Footy on Monday night.

"I'm cautiously optimistic, we're certainly not going down the path of talking about retirement – that's what people want to talk about but I'm cautiously optimistic that he'll come back.

"He's a favourite of ours and he's a favourite of mine."

Scott said he was in favour of scrapping the League's substitute rule and supported a reduction in the number of interchange rotations.

"We're already planning for it (the sub rule) to be gone," he said.

"We haven’t had any indication from the AFL that that'll be the case, but I think the groundswell is growing and interchange is not the issue we probably thought it was.

"I'm happy for interchange to come down if that's what the powers-to-be want to do."

When asked if there was an appropriate interchange cap number per game in the event of a rule change, Scott said: "I don't think there is a perfect number.

"If it was between 60 and 80 (rotations), it wouldn’t worry me.

"The only thing with abolishing the sub rule is if you do get a couple of injuries early, you can’t have the opposition increase rotations against you and if you reduce interchanges, that'll solve it."