NICK Riewoldt would have retired without hesitation had doctors told him to after his sickening concussion in round seven this year.

The 32-year-old was taken to hospital after the brutal front-on collision with Adelaide's Brodie Smith that left him unconscious during the first quarter.

The game was held up for six minutes as Riewoldt was stabilised by medical staff and taken from the field. 

It was a graphic incident that led to game greats Leigh Matthews and Jonathan Brown calling for Riewoldt to seriously consider his future after five head knocks in recent seasons. 

A candid Riewoldt, who became a father for the first time to son James late last year, recently told AFL.com.au he would have quit if the medical advice had suggested it.   

"If I'd been told I couldn't keep playing – and 'Goose' [former St Kilda and Brisbane Lions defender Matt Maguire] has just gone through it, when it's presented like that – it's pretty hard to argue," Riewoldt said.

"I think it's good that when it gets to that stage, it's really taken out of the players' hands." 

At the time, Riewoldt was on 285 games and in his second week back from a calf injury sustained in round two against Gold Coast.

He's contracted for another season and is well within reach of becoming the fifth St Kilda player to reach 300 games.

In the weeks after the incident, Riewoldt went through a battery of concussion tests and consulted plenty of medical staff, including a neuropsychologist, before returning in round nine.

"I wanted to keep playing. I didn't think about it from a sense of wanting to … but I did think it might be a possibility that would be out of my control," he said.

"It was on the radar, but it would only have been because the doctors told me to. 

"But they didn't, they gave me a clean bill of health, I passed everything I needed to pass, I was comfortable and my wife and my family were comfortable."

Riewoldt faces a race against time this week to prove he can play against Richmond on Sunday, despite suffering a low-level calf strain against Greater Western Sydney on the weekend.

He'll be doing everything he can to play in 'Maddie's Match' against his cousin Jack's Tigers, with the game to raise funds for Maddie Riewoldt's Vision, the charity organisation established in honour of his late sister.

Maddie died in February this year after a battle with aplastic anaemia, which is a bone marrow failure syndrome.

In an interview conducted before he suffered his latest injury, he said an interrupted pre-season had contributed to the calf injury in round two that kept him out for three games.

"I've never really had too many soft tissue injuries," he said.

"My pre-season was really disjointed with everything that was going on.

"There was a really high level of stress and anxiety, which are pretty big precursors.

"It was just down to an interrupted pre-season."

For more information on Maddie Riewoldt's Vision, visit www.mrv.org.au. 

Nick Riewoldt received a clean bill of health after being concussed against Adelaide. Picture: AFL Media