A series of concussions has forced North Melbourne utility Leigh Adams into an early AFL retirement.

The Kangaroos made the announcement before Saturday night’s match against Carlton and said it is a medical decision.

Adams, 27, had played 104 games since his 2007 senior debut.

Renowned as a tough player who would burrow into stoppages, Adams had not played any AFL games this season because of his concussions.

North said Adams is back at full fitness and has no lingering issues, but had to put his health and future first.

Adams told teammates on Friday that he had retired.

“It’s a real credit to `Patch’ that in my view, he redefined that forward/midfielder role in today’s footy,” coach Brad Scott said in a club statement.

“He really did play that role as well as any player in the competition.

“Patch was such a highly valued person and highly valued performer for us over such a long period.

“But we know there are things that are more important than the game.”

Adams suffered three head knocks last year, eventually forcing him out of the finals.

He suffered another concussion during a VFL pre-season match.

Adams returned to the VFL, but after three games he suffered another head knock and he had not played since.

In June, Adams spoke about the latest head knock had also led to a short-term struggle with depression.

Adams said he decided to retire after advice from his neurologist.

“I’m at a trend at the moment where I’m having smaller hits that are having signs of lasting for longer than they should,” he told the Seven Network.

“If I was to keep going down that path, maybe there could be some longer-term effects.

“It was on his advice, to retire from contact sports.

“I’m healthy now and, if I can walk away from the game (with full health) … it was a pretty easy decision.”