Former Brisbane Lions defender Matt Maguire, who was forced into premature retirement after a series of concussions, has urged South Sydney youngster Kyle Turner to be as honest as he can with medical staff about how he is feeling and to not let his age affect any decision he makes about his future as a result after multiple head knocks.

During 14 seasons in the AFL playing for Brisbane and St Kilda before that, Maguire said he was knocked out on four occasions and concussed a total of seven times. The 31-year-old copped a heavy knock in a NEAFL game in April which prompted him to retire two months later, citing ongoing symptoms linked to the concussion.

Four months on and Maguire says he is "definitely not back to full health". The 170-gamer is still unable to exercise or do anything at a high intensity.

Although Turner, who has been concussed several times in his short NRL career, was assessed by medical staff after being knocked out cold in South Sydney's win over Penrith on Sunday and is unlikely to spend any time on the sideline, Maguire offered his advice to Walker – be careful and remember that health always comes first.

"I would definitely urge him to be honest with the way that he's feeling, knowing what I've been through," Maguire said. "I think there were times when I pushed the envelope when I was young, coming back from a concussion. Maybe it might have been a week too soon, or a couple of days too soon, because you do have an insatiable appetite to play and compete. When you're young, you're quite naive and want to keep playing. I would definitely urge him to err on the side of caution and closely monitor how he is feeling and recovering from training."

Turner was returning from a serious neck injury he suffered during pre-season when he was knocked out attempting a tackle on Penrith's Jeremy Latimore. The sickening collision prompted Alex McKinnon to tweet that he felt sick, while Gorden Tallis went further by saying if his son was in the same position he would ask him to retire.

Maguire said he would never suggest that Turner retire because he does not know the ins and outs of his situation, but he did empathise with the 23-year-old who might have no other choice but to cut his career short – an extremely difficult thing to do given his youth.

"Being 31 and having to retire from concussions and knowing you will probably never play a game that you've loved for 20 years of your life, having to put a stop to it at my age was a tough decision," Maguire said. "The fact that he could maybe have 10 more years in the game, it would be a very daunting prospect to have to make that decision and come to the realisation if it [retirement] is what needs to be done for his health.

"If I was talking to Kyle, I would want to know how he's actually feeling and if he actually feels like he's normal and he's able to do everything to the best of his ability, I wouldn't have an issue with him going out there and going back to playing. But I think it's up to the individual."