Australia remain hopeful that captain Pat Cummins will be fit for the first Ashes Test against England in November but coach Andrew McDonald says it is getting "tight".

The 32-year-old pace bowler has not played since suffering a back injury against the West Indies in July. Australian media reported on Wednesday that he will miss the first Test in Perth on 21 November and is doubtful for the whole series.

On Friday McDonald said there was "a lot more positivity" surrounding the skipper's chances of playing in the opening Test but he would need at least "four, four-and-a-half weeks" of bowling practice to condition his body for the rigours of Ashes cricket. The first Test is six weeks away.

"The reality is, we're starting to get tight in terms of the times," McDonald said. "We're still optimistic, hopeful, but this time next week, I think we'll be in a position to get a better gauge on where he's at."

McDonald said he would weigh up whether Cummins could be included in the side even if he was a "little bit underdone". Cummins has taken 309 Test wickets at an average of 22.10 runs per dismissal. He is even more formidable in Australia, taking 177 wickets at 19.92, while he has also taken 91 wickets against England in 19 matches.

England vice-captain Harry Brook said it would be a "bonus" if Cummins was to miss out but warned that they could not take any replacement lightly.

"Pat Cummins is a phenomenal bowler and has been for so many years now," said Brook on BBC Radio 5 Live. "He's got incredible skill at high pace and if he's not there it's a bonus for us.

"But they have got lots of amazing bowlers so I'm sure they'll draft someone in who is very skillful. We can't take anyone lightly."

Brook is also confident that England captain Ben Stokes will be fit to lead his side through all five Tests this winter. Stokes has been troubled with a shoulder injury since the Test series against India, and has not completed any of their past four series.

"I don't have to do much as vice-captain," added Brook. "Everyone knows what Stokesy's like, he's an incredible leader. Everything he does on and off the field is awesome.

"I'm looking forward to working alongside him. I have complete faith in him getting through all five Tests. He's a warrior and he'll try his hardest.

"We are confident going out there and looking forward to the challenge."