Miller is looking for a new club after negotiating a release from his contract with MLS club Vancouver Whitecaps.
The free agent has been linked with a return to Rangers, where he has spent two spells in the past, this summer.
The Gers fan, who has trained at Murray Park during the MLS close season, stressed he had not spoken to Gers anager McCoist.
But the 34-year-old is confident he can carry on for some time after undergoing a successful knee operation in November last year.
He said: "Realistically, I think I can play on for another three years anyway. I feel as fit as I have ever been. Obviously, I am getting older, but I still feel great.
"After the operation I have had this season I have felt like a new man to be honest. I have hopefully got a few years left in me yet."
Miller, who retired from international football last year after winning 69 caps, spent two spells at Rangers between 2000 and 2001 and from 2008 to 2011.
And he refused to rule out returning to the Glasgow giants to help them complete the final stage of "The Journey" back to the top flight.
Asked specifically if he had held talks about joining the Light Blues, he said: "That has not been discussed yet."
"There is nothing in place as yet. I have six or seven weeks to get a holiday with the family, which I have not had in a couple of years.
"Then we can sit down and my agent can earn his money and hopefully find me a new club come July 1.
"I wouldn't rule anything out. I will look at all options. It is just a case of my agent getting down to work now and finding us a new club."