Pat Cummins is eying off a return to bowling within weeks in a bid to avoid spending the majority of the Ashes series on the sidelines.
Cummins conceded publicly for the first time on Monday he was unlikely to feature in the first Test in Perth on November 21, with time running out for a comeback.
But the Test captain said if he was not fit for the series opener he hoped to be "very close" to playing by the time Australia took the field at Optus Stadium.
Cummins hasn't bowled since Australia's 3-0 defeat of the West Indies in July, with scans later detecting a stress injury in his lower back.
This week looms as crucial in Cummins' bid to return to play, given the pace ace wants to be bowling for at least a month before lining up in a match.
Asked on Monday what chance he was of playing at Optus Stadium in five-and-a-half weeks, Cummins admitted it was not high.
"I'd say probably less likely than likely," the quick told reporters at Fox Cricket's summer launch.
"I've still got a bit of time.
"I'm actually feeling really good at the moment. A few of the symptoms hung around for a little bit longer than I would have liked, but they're all gone now."
After resuming running last week, Cummins hopes to add more work to his body over the next week to the point where he is in a transition towards bowling.
That will include exercises with medicine balls and side holds, aimed at gearing his body for a return to the bowing crease.
"I'm running today and running every second day," Cummins said.
"Each run's a little bit longer and then we get into slight bowling prep I think next week.
"I'm probably a couple of weeks away before I actually put on the spikes and bowl on the turf.
"But it's been a good couple of weeks. Each session feels better and better."
If Cummins is out, Scott Boland would loom as the obvious replacement after spending the past four years as the world's best back-up quick.
But Australia could dearly do with their captain against an English side already talking up this summer as their best chance to win down under in years.
Cummins insisted on Monday it was still too early to know how much of the series he could miss, with coaching staff bullish on the his chances.
But working in his favour at least is the drawn-out nature of the first three Tests in Perth, Brisbane and Adelaide.
Each of the three matches start almost a fortnight apart, meaning Brisbane is still seven-and-a-half weeks away and Adelaide more than nine.
"The immediate goal is to make sure I'm giving myself a chance to be right for as much of it as possible," Cummins said.
"It's really too early to kind of make some big decisions. You're just trying to tick off each session.
"With these things, it's pretty hard to go from not bowling or anything at all to suddenly playing five Tests.
"The first step is trying to give us a shot at being right, and then we'll work it out a bit closer."
Cummins will fly to Perth with the Australian team, regardless of whether he plays.
"Even if that first Test I'm not playing, I'm hopefully very close to playing and prepping," Cummins said.
"And that's where all the physios and coaches and players are."
