The rugby league great turned pugilist even concedes his December 10 grudge match with Manly prop Josh Aloiai in Newcastle could be his last hurrah.

He knows he can't box on forever.

"I really do enjoy the challenge but I do admit there's not much left in the old body," Gallen said.

"I've got a three-fight deal with No Limit (Boxing). Whether I see the three fights out, I'm not sure.

"I've built a great life for myself and my family and there's going to come a time when I need to start enjoying that.

"So I don't have a lot left in me but I've got enough to get this bloke done, that's for sure."

Gallen is financially set for life.

But after being left battered and bruised after the first defeat of professional boxing career last outing against Australian heavyweight champion Justin Huni in June, the cross-code warrior wants to stop and smell the roses.

"I go to barbecues - I went to a barbecue on the weekend and I didn't drink," he said.

"I want to start enjoying that side of my life. I want to start enjoying my kids a bit more and there's going to come a time when it's going to stop and it's not too far away.

"I've done alright. I'm in a good position financially so I'm doing OK. There's not a dollar figure I need to hit. I'm pretty good at the moment.

"It's just about when I'm sick of getting up and going for a run in the morning and when I'm sick of going out and getting punched in the head for training.

"There's been a few times in this camp where I 've got up and got it done and that's what being disciplined in sport is all about - getting up and doing it when you don't want to do it.

"And I'm still doing it at the moment but there's going to come a time when it's going to stop."

Cronulla's only ever NRL premiership-winning captain and triumphant 2014 NSW State of Origin series skipper feels blessed not to have suffered any long-term brain injuries while forging one of the toughest careers of modern era.

But he doesn't fancy tempting fate much longer.

"I've been really lucky," Gallen said.

"I've played over 400 games of top-class footy and I was never knocked out once.

"I had two concussion tests in my life and one of them I didn't need. The other one I passed easily.

"So I've been lucky. Will it worry me in 10 years' time, we'll wait and see.

"But I'm OK at the moment."

Australian Associated Press