The 31-year-old South Australian, who was dumped after three Ashes Tests in England last year after taking just three wickets at an average of 100, is facing selection pressure from Australia's fast-bowling new breed - Shaun Tait and Mitchell Johnson.
Although Gillespie unexpectedly regained his Test place during April's tour of Bangladesh, claiming eight wickets in the two Tests at an average of 11.25 and an amazing 201 not out in the second Test - creating history as a nightwatchman - he accepts he may never again play for Australia.
Gillespie would love to retain his place for the first Ashes Test, beginning in Brisbane on Nov 23, but he believes it is time to consider the next generation.
"You've got to be a realist sometimes," Gillespie told The Australian newspaper Thursday.
"They (the selectors) can afford to go for an inexperienced young punk because how much experience is in that bowling attack?"
Glenn McGrath, Shane Warne and Brett Lee collectively have 1,438 wickets from 313 Tests.
"You can have a young fellow come on first change like a Tait or a Johnson and let them loose. Give them a bit of free rein," he said. "Let them enjoy themselves and have a good time. I reckon it would be a great thing if they picked a young bloke."
"With Tait or Johnson you get a bit of an X-factor. Tait can run through teams. He bowls with genuine pace, swinging yorkers and he's unpredictable. He's got some serious talent.
"Young Mitch is an extremely talented bowler. He's fast and he swings them. He gives you left-arm variety. He's obviously very green, but he's got plenty to offer.
"He just needs to trust his body, and he will as he fills out a bit more and gets stronger. He's going to be the real deal, I think."
Tait, 23, made a modest Test debut on last year's Ashes tour after dominating for his South Australian state and has since been forced to overcome shoulder and back injuries.
Johnson, 25 next month, has been injury-plagued for much of his career since fast bowling great Dennis Lillee saw him at 16 and announced that he was the best young paceman he had seen in a decade.
He impressed on the recent one-day tour of Malaysia, claiming six wickets in two matches, including 4-11 against India.