The pace bowler has secured 309 wickets in 71 five-day games with an stellar bowling average.
The Australian chief selector the selector has stated that skipper Cummins will be a central figure in this winter's historic rivalry.
There were concerns that the 32-year-old might sit out due to a stress fracture in his back that remained unresolved.
Initial reports from team management suggested no final decision had been made regarding Cummins' participation, with the five-Test series scheduled to begin on November 21 in the WACA.
Bailey expressed that Cummins is "building up" and remained hopeful about the prospects of participating.
"We know that the clock is ticking and various factors at play, not just his injury, but other factors as well," the selector added.
"We're encouraged. We firmly believe that he's going to play a key capacity. Ideally it's the first Test. If not, we'll adjust."
Injury History
The captain missed the ODI and T20 games against New Zealand and India in the previous weeks after medical tests showed a lumbar bone stress.
He has a history of recurring issues, with flare-ups in 2012-13, 2013-14 and 2015-16 forcing him out of three Australian summers in a short span.
Cummins stated he would be ""aggressive" and "take risks" in his recovery plan to ensure his availability for the Ashes.
He mentioned that he did not know if the captain had resumed bowling as part of his recovery but acknowledged it was "getting tight" for him to regain fitness for the first Test.
Backup Options
Should Cummins not be fit, veteran batsman Smith will assume leadership.
Versatile player Green was withdrawn recently from Australia's squad for their one-day international series against the Asian giants as a preventive step because of discomfort in his torso.
The selector characterized it as a "small issue and stated that he'll feature in the domestic first-class competition, so will be "ideally positioned to resume bowling."
"Extensive planning has gone into creating the schedule for him to participate for the first Test as an all-rounder," the selector detailed.
"His involvement was limited to the starting games regardless. His aggressive style the bat in limited-overs, should it hinder progress for another day, we opted to approach this more conservatively."
Series Schedule
Australia vs England: The Ashes
Spanning from late 2025 to early 2026
