Joe Root plans to give Ben Stokes and Jonny Bairstow as much time as possible to be fit for a fifth and final Ashes Test in which he challenged England to show "fight" and "desire" from "ball one".

Star all-rounder Stokes has already confirmed in his column for The Mirror that he will not be able to bowl in the day-night Test in Hobart having suffered a "low grade tear" in his side during the gritty draw in Sydney that ensured Australia cannot secure a 5-0 series whitewash.

Jonny Bairstow scored a gutsy first-innings century in that match but was forced to play through the pain barrier after receiving a hefty blow on the thumb from Pat Cummins, an injury that meant he could not regain the gloves from Jos Buttler, who has travelled home with a broken thumb, in the second innings.

Captain Root said both men will be assessed over the next couple of days before a decision is made.

"We've got to just see where they're at over the next couple of days, see what their bodies can handle and then assess from there," Root told a news conference on Wednesday.

"Certainly you can pick Ben as a bat, Jonny too. We have to see where they are at, what their bodies can handle.

"You have to trust the medical advice. Those guys work tirelessly to make sure we are in the best possible position to go and win games and sometimes that is making some difficult calls.

"I think they need to make sure they feel like they're physically in a place where they can get through five days of hard cricket, whatever Australia throw at them, and they're in a position where they can go out and play and firstly, get through the game, but also, most importantly put in a performance as they managed to last week as well. 

"It's alright being fit to play but you've got to be fit to perform and I think that's what we've got to work out."

Stokes made two half centuries in Sydney, while Bairstow made a hard-earned 41 in the second to add to his century with both men proving crucial as England bravely fought for a draw after being heavily beaten in each of the first three Tests.

England were still largely outplayed by the hosts and had to dig deep to avoid defeat. Root wants to see the same kind of guts throughout the duration of the contest in Hobart.

"On the back of three very difficult games where we underperformed, to come back and get something from the last game showed a great amount of character," he added.

"There was an element of relief managing to get through those last few overs but the desire, the fight and the pride that everyone showed on that last day is something we have to harness.

"We have to play like that more frequently through the five days, not just on the last day when everything is on the line, but from ball one. We've proved to ourselves that we can do it, now can we take it a step further?

"Can we make sure we do it in a winning cause rather than just trying to save a Test match? We have something to build on – that’s what we have to take from the last game and into this one."