ADELAIDE defender Scott Stevens believes the AFL and the clubs are doing enough to help prevent and manage concussion in players, despite being forced into early retirement because of multiple head knocks.

Stevens has been battling the symptoms of post-concussion syndrome, including headaches, nausea and blurred vision since sustaining two minor knocks to his head at training in April this year.

The 29-year-old hasn't played or trained fully since round three, and on Tuesday announced his 144-game career was over.

He's expected to make a full recovery, but said he wasn't prepared to risk suffering a recurrence of the condition if he returned to the field and received another hit to his head.

Stevens' post-concussion illness can't be traced back to one particular incident, with his specialists believing the condition to be the result of a combination of repeat concussions and genetics.

Prior to the start of the season, the League altered its concussion policy so that a player diagnosed with concussion was not allowed to return to a game or training on the day of the injury.

There have already been several high-profile casualties of concussion this season, including forwards Jack and Nick Riewoldt and Geelong star Jimmy Bartel.

The AFL has also moved to offer more protection to a player with his head over the ball, with recent changes to the head-high contact rule.

Stevens has a history of adverse reactions to concussion, and said it was important people understood his case was an unusual one.

"Every concussion is different and how one player reacts to it is different to how another player reacts to it," he said on Tuesday.

"All doctors in the AFL care for their players and coaches do as well. Sometimes, players are right to go back on [after a head knock] or play the next week.

"Unfortunately for me, I wasn't."

Earlier this year, former Melbourne defender Daniel Bell announced he would be seeking compensation after being diagnosed with brain damage linked to multiple concussions sustained during his playing career.

Stevens has been reassured his current condition won't lead to long-term problems, and said he was comfortable with the existing rules of the game relating to concussion.

"It's a great game, AFL, and it would be hard to change it," he said.

"The way it's played is fantastic. It's getting quicker and there are more collisions, no doubt, but as long as the care is still there from doctors and clubs, there's no reason for [the rules to change]."

Crows coach Neil Craig said the situation with Stevens, which saw him excused from training for 10 weeks, highlighted the emphasis clubs placed on player welfare.

"The playing group are the most important people in your footy club, so we have an absolute responsibility in terms of their welfare and safety and to keep that in the highest regard," Craig said.

"Our club has been really responsible in this situation with Scott. It would've been very easy for me as a coach to put pressure on Scott and say, 'come on, we need you', particularly with how the year's going at the moment.

"I've tried my absolute best not to do it even though there have been times we would've loved Scott to be playing in defence for us."

Katrina Gill covers Adelaide news for afl.com.au. Follow her on Twitter: @AFL_KatrinaGill