The Greater Western Sydney ruckman confirmed on Friday he had retired, his body worn out after a decade of being a battering ram and enforcer for Geelong, the Swans and Giants.

A navicular foot injury in the qualifying final against Adelaide was the final blow in a 172-game career that began when he was taken as a mature-age recruit from the Gippsland town of Bunyip by the Cats in the 2007 rookie draft.

"It's a bit of a sad day for me but, obviously, something I have to do. I am grateful that I was able to play at the highest level for 10 years. Who would have thought the fat kid from Bunyip would have been able to last this long?" Mumford said.

He famously shed 20 kilograms in 2007-08 to turn himself into an elite footballer.

"I have just about injured every part of my body throughout my career. I think the foot was the turning point. I have, obviously, had problems with the knees for many years," Mumford said.

"The ankle was reconstructed. To injure the footy the way I did as well - I want to be able to run around with my kid (Oliver) in the years to come. By me pushing through and trying to keep on playing, there was the potential to so more damage and, for me, it was just not worth the risk."

With coach Leon Cameron alongside him, Mumford, with a year to run on his contract, said he had been pondering the decision for several weeks. The final call was made easier by accepting the Giants' offer to be ruck coach next year, helping to develop Rory Lobb, Dawson Simpson, pinch-hitter Jon Patton and the uncapped Matthew Flynn, the latter taken in the 2015 national draft.

"Once I found out there was potential for it (foot) to, obviously, get worse, I had to make the tough decision of hanging the boots up," Mumford said.

"It's been floating around in my mind for a while now. Obviously, it's taken a bit of time now to come to the decision but I just figured, for me to play on and not be at 100 per cent, it's almost selfish. I would much rather finish up while I was still playing some good football."

Mumford, 31, had struggled to train this year because of knee problems but was still regarded as central to the Giants' premiership hopes.

The Giants are in the premiership "window" and this was one reason that made his decision difficult to accept.

"That's what made my decision harder, knowing the boys are going to be pushing for finals year after year," Mumford said.

"For me to hang around (as ruck coach) and do as much as I can to make things happen, give us the best chance of going all the way to win the grand final, is something that excites me."

He played 21 matches for the Cats before he was traded to the Swans after the 2009 season for selection 28, which the Cats used to take Mitch Duncan. He would play 79 games for the Swans, including being a pivotal figure in their 2012 premiership. He was traded to the Giants in 2013 for selection 39.

Cameron said Mumford had enjoyed a "remarkable career" and had been a "great warrior" for the Giants.

"It's sad to see him go out this way but he has to look after his life. He is a credit to himself and his family," Cameron said.

"People tend to forget he was the No.1 ruckman at the Swans when they won that flag. He has a medal around his neck for winning a premiership which a lot of players can't say they have. He can look back and say he got absolutely everything out of himself."??????

Lobb, who was given the ruck responsibilities after Mumford was hurt, is likely to be the Giants' front-line big man next year. Mumford's retirement could also mean more opportunity for Simpson, who has managed only two senior games since joining the club after the 2015 season.

Mumford, the Giants' 2014 best and fairest, said Lobb had the ability to do the job.

"We saw in the last couple of games in the year when he did get his chance just how good a footy he can play. I have no doubt, after I really rip into him next pre-season, he will come out flying," he said.

Mumford's standing in the sport prompted Swans chief executive Andrew Ireland to also acknowledge his career.

"From the moment Shane joined us in 2009, he made an immediate impact and certainly made his presence felt on and off the field," Ireland said.

"While he was a tough and fierce ruckman, he was the ultimate teammate and an extremely popular and fun person to have around the club. As a premiership player, Shane will always hold a special place at our club."