"I haven't really stopped playing footy, so my fitness is pretty high," Walker told Fairfax Media.
"I've probably lost about 10 per cent of speed, but I make up for that with experience. We can do things with the Brumbies and set it back on the right track again.
"The fire is still blazing, as soon as I threw the jumper on last weekend it turned into a bonfire. I was thinking, 'how good is this?'.
Walker, who played seven Tests for the Wallabies and 145 games of NRL, and one Test for the Kangaroos, has kept fit playing rugby league in Brisbane where he works as a personal trainer.
"I really, really love the Brumbies, so if there was anything I could do to help, then I'd do it in a heartbeat," he said.
If Walker does sign he will become the oldest player to do so in Super Rugby, surpassing Brad Thorn, who was 39.
- AAP