Australia captain Pat Cummins said on Monday he was more likely than not to miss the first Ashes test in Perth next month and is not absolutely certain of being fit for the second in Brisbane.

A back stress injury has Cummins racing against time to be fit for the first day of the Ashes opener on November 21, with the paceman yet to resume bowling in his rehabilitation period.

“I wouldn’t put percentage on it, but I’d say probably less likely than likely, but I’ve still got a bit of time,” the 32-year-old told reporters in Sydney.

“We get into bowling preparation I think next week, so probably a couple of weeks away before actually putting on the spikes and bowling out on turf. But it’s been a good couple of weeks, each session feels better and better.”

Australia coach Andrew McDonald said on Friday that Cummins probably needed to be back bowling a minimum of four weeks to have a chance of playing in Perth without running the risk of further injury.

“You’d want at least, probably a month in the nets,” Cummins said.

“If you play a test match, you want to make sure you’re right to bowl 20 overs in a day and you don’t have to really think about it.

“So four weeks is pretty tight. But I think somewhere around

that mark.”

Given he has not started bowling yet, Cummins said he was not prepared to commit to being ready to play the day-night second Ashes test at the Gabba starting on December 4.

“I think it’s a bit early to know with these things,” Cummins added.

“It’s pretty hard to go from not bowling or anything at all to suddenly playing five tests. So, first step is trying to kind of give us a shot at being right, and then work it out closer.”

Cummins has been ever-present in Ashes clashes since his first test against England in the 2017-18 series, helping Australia first win back and then retain the urn ever since.

“Some days I’m kind of annoyed because of the Ashes and it’s a big summer and then other days I’m realistic,” he said.

“I’ve had the last seven or eight years almost uninterrupted home summers, so I feel like that’s a really good run as a fast bowler. Maybe it’s my turn.”

If Cummins is not fit to play in Perth, former skipper Steve Smith is likely to captain the team with Scott Boland replacing him in the pace attack.

“I think in the last few years, one of the things we’ve done really well is when someone’s missed out, someone stepped straight in and done a brilliant job,” said Cummins.