The Ashes: Australian captain Michael Clarke struggling to be fit for the first Test

Michael Clarke has been ruled out of Australia's tour of India (GETTY IMAGES)

Australia's captain Michael Clarke has admitted he is no certainty to be ready for the first Ashes Test against England next month.

Clarke was ruled out of Australia's tour of India, where they will play the hosts in one Twenty20 and seven one-day internationals, due to his long-standing back injury.

The 32-year-old has been suffering with the problem for some time and it restricted his participation in the limited-overs matches in England during the summer.

Clarke remains doubtful for the first Test at The Gabba in Brisbane which begins on 21 November. "I'll say definitely not [a chance of missing the first Test], but at this stage, we can't predict how long it's going to take to get right," he said.

"If you ask Alex [Australia's physio Alex Kountouris], I'm sure he'll say there is that chance. For me personally, I'm trying not to look at that. It's about being nice and positive and working my backside off and getting myself right."

The timing of the limited-overs series in India has been questioned, with the final game to be played just 19 days before that first Test.

England, who hold the Ashes after their 3-0 series win in the summer, arrive in Australia on 25 October, but Clarke said there would be no advantage in arriving ahead of the hosts.

"Every player's different," he said. "For me personally, the way to prepare for any series is to score runs in whatever form. It makes no difference."