GIANTS coach Leon Cameron admits his club will take a "calculated risk" when it adds Shane Mumford to its list on Saturday.

Cameron confirmed that the GIANTS will sign Mumford, who retired at the end of the 2017 season with a serious foot injury, under the competition's new supplemental selection period on December 1.

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Mumford's return to the GIANTS will cap a remarkable 12 months for the former club champion, who was the club's ruck coach last season.

The 32-year-old flagged his intentions to come out of retirement at the end of the 2018 season, before he was embroiled in controversy last month after a video emerged of Mumford snorting a white powder.

He was fined $25,000 and suspended for two matches by the club, and Cameron said the incident – that occurred three years ago - didn't reflect the character of the player he's worked closely with since 2014.

"I'm a believer of second chances and guys make mistakes in life, and Shane made a really big one," he said.

"We'll work with him closely to make sure he makes better decisions.

"He's determined to make the wrongs right and we'll be there to help him through that.

"It's a wonderful story, it's an interesting story, and no doubt plenty is going to be written about it.

"We look forward to the journey and we know there'll be some ups and downs, but that’s like any club."

Mumford's foot issue was so serious that when he retired, he said he was forced to give the game away or risk permanent damage to his body.

Cameron said the GIANTS have put plenty of time into the ruckman's injury but there's no guarantee Mumford will return to the AFL and be the player he once was. 

"How do you know (his body will stand up) in March, April and May when you're playing back to back-to-back (games)?" he said. 

"But we're willing to take a calculated risk because we've done all the research on him. 

"Am I really confident that his attitude and his application is spot on? Yes, it is. 

"The way he's gone about his boxing and his cross-training in his own time and present himself in a manner that we think can stand up to AFL footy has been great. 

"But if you look back at history, it's really hard to come back after a year out.

"The most important thing is that Shane is really driven and when he's driven, he can do some things." 

Mumford, who turned his attention to boxing when his footy career was ended and won both his professional fights this year, will begin officially training with the GIANTS on Saturday. 

Cameron ruled out any more bouts for his big man while he's in-season, but hinted that Mumford could step back into the ring in the off-season. 

"He's got a passion for it and he actually thinks he's Muhammad Ali at 2-0, and I'm not going to take that away from him," Cameron said. 

"The training he does is really beneficial for him and if that helps him in his return from retirement, then we'd be mad not to explore that."