Lillee warned that Australia's senior batsmen could be its undoing in the most-anticipated Test series for many years.
Writing in his column in The West Australian newspaper, Lillee said as a fast bowler he always welcomed the chance to bowl against ageing English batsman such as Colin Cowdrey, who played in the 1974-75 series at the age of 42.
Lillee, now president of the Western Australian Cricket Association, said he used to "lick his lips" at the prospect of bowling to an English team dubbed "Dad's Army".
He warned that Australia was now in the same boat, with a great, but ageing team.
Lillee noted that opener Justin Langer will be 36 when the series begins at the Gabba on Nov 23, while Matthew Hayden, Damien Martyn and Adam Gilchrist will all be 35.
He said the English bowling attack will take great confidence into the series.
"Over a period of time, as a fast bowler, you get to learn that a batsman's reflexes definitely get slower as he gets older," he wrote.
"Mark my word, the England pace attack, mentally buoyed and on faster Australian wickets, will this summer be at their absolute peak age-wise.
"It doesn't matter how fit a batsman is - his reflexes are just not going to get any better as he gets older, so problems are harder to hide.
"I'm not having a go at individuals, it's just that this is what happens.
"Australia have some great players but even the greatest players get tapped on the shoulder by Father Time at some stage.
"We've got to wonder if that time has arrived for some of them."
Lillee said captain Ricky Ponting and middle-order star Mike Hussey are at the peak of their powers, but added that the probable absence of promising pair Michael Clarke and Phil Jaques will hurt the Australians.
Although he expects Gilchrist to perform better than in last year's Ashes series in England, he said if the visitors could contain the left-hander's explosive batting it would greatly harm Australia's cause.
He said Langer was another Australian to face a significant challenge, having not played Test cricket since being hit in the head by a Makhaya Ntini delivery against South Africa earlier this year.
Australia is a short-priced favourite to reclaim the Ashes when the series begins next month.
However, Lillee, who claimed 355 wickets in 70 Tests from 1971-84, has grave doubts that the home side can live up to expectations.
"It's worrying how Australia, after being outplayed in England, are going to turn things around with a decidedly older team," he wrote.
"I'm afraid there are danger signs for Australia as the most-anticipated Ashes series for years heads our way."