Warne, who is in Perth for the third Ashes Test, feels that he is fit in general but needs more time and dedication to bowl the required long spells in a Test match.
"I must say I was very flattered and surprised that a lot of you out there wanted me to make a comeback and play in the series. Of course I would love to be out there in the thick of it, but if there was to be a comeback I would need time to get match-fit," Warne wrote in his column for The Herald Sun.
"My general fitness is as good as it has ever been - I have worked hard on that lately - but toiling away for long spells and backing up the next day takes time, practice, lots of physiotherapy and even more dedication.
"I must admit it did cross my mind, but then I woke up in London, where it was snowing, and realised I was only dreaming.
"So, I am sorry to disappoint you, but there will be no comeback in this Ashes series," he wrote.
Warne, however, insisted that he will continue to help the struggling Australian team. "I will continue to help the Aussie boys any way I can in their quest to reclaim the Ashes.
"I think they will win this match because they know the conditions better. They also know the length to bowl, which will help them take 20 wickets."
"The boys have been under the pump since Adelaide and I reckon the team will jell and be ready to perform.
"Whether Australia bats or bowls is irrelevant.
"It is about giving the English something to think about, start them doubting themselves and worrying about Australia."
If the home team loses in Perth, Warne sees major changes in the side for the remainder of the series.
"The way the Australian team plays this week will give us an indication of where it is really at. If the team fails here, then there will be some big changes at the end of the series, but a win could change everything."