GIANTS ruckman Shane Mumford says his body is "well and truly destroyed", but the veteran is determined to go out with a bang in an attempt to lead the GIANTS to an unlikely premiership.

Mumford first retired as a 31-year-old at the end of 2017, but has remarkably strung together three more seasons since being lured back to the game in 2019.

With a motto of "never say never", Mumford hasn't completely ruled out playing on next year.

But at 35 years of age and nursing a chronic back injury, Mumford knows 2021 will almost certainly be his last as a player.

"My body is well and truly destroyed," Mumford told AAP ahead of Saturday's elimination final against Sydney in Launceston.

"My back is the thing that has been giving me the most grief this year.

"My knees and ankles are always going to be there in the background, but at the moment it's more my back that's been holding me up.

"I'm a never say never kind of guy, but there's a fair chance I'll just be coaching rather than be playing next year."

Mumford has been carefully managed this season, with the GIANTS playing him for a maximum two games in a row before giving him a rest.

It's a strategy that has worked well, but it remains unclear what will happen if the GIANTS go deep into the finals.

Kieren Briggs, with just five AFL games to his name, led the ruck against Carlton in the absence of Mumford last week.

And former Demons and Kangaroos ruckman Braydon Preuss, who is yet to debut for the GIANTS, is also now available for selection after overcoming a shoulder and pectoral injury.

Mumford is unsure which way selection will fall, but he's determined to back-up for as many games as possible if the GIANTS can keep winning.

"It's going to be great watching the three of us fighting for positions in the team," Mumford said.

"That's going to be a good problem for the selectors to have this week.

"With me it's more a week-to-week sort of thing (with my body).

"We found out during the year that two games in a row was pretty good, and then after that I was starting to get too sore to be playing at my best.

"But being finals, I'll be trying to get myself up for as many as possible."

Mumford played a key enforcer role when the GIANTS beat Sydney in a physical qualifying final in 2016.