Joe Root is drawing up plans to stop another Usman Khawaja masterclass as England prepare to make a call on injured stars Ben Stokes and Jonny Bairstow.

Australia are expected to retain Khawaja in their XI for the fifth Ashes Test, with under-pressure opener Marcus Harris making way for Travis Head's return.

Khawaja cast doubt on his own prospects of playing in Hobart despite becoming just the third man to celebrate twin tons in a SCG Test.

But several signs at training on Wednesday night, when Harris batted in the nets alongside the squad's bowlers, pointed to Khawaja opening alongside David Warner.

Root is certain the left-hander will take part in the pink-ball Test beginning on Friday, admitting he was surprised Khawaja didn't play the entire series.

"He's a wonderful player," England's captain said.

"It was a phenomenal effort. What he managed to achieve last week was truly brilliant, so we need to make sure we keep him quiet as best we can.

"We've got some work to do."

The tourists are fresh from their best performance of a long summer, having survived 102 overs to salvage a draw in Sydney and remove an ignominious 5-0 series loss from the equation.

But it came at a major cost.

Stokes (side strain), Bairstow (thumb) and Jos Buttler (fractured finger) all suffered injuries during the fourth Test.

Buttler has already returned home.

Sydney Thunder's Sam Billings worked on his keeping for much of Wednesday's training session and is expected to make his Test debut at Bellerive.

Stokes and Bairstow are racing the clock as they seek to convince Root, coach Chris Silverwood and medicos they are ready to take on Australia.

The pair are potential match-winners with the bat, while they faced a combined 228 deliveries to provide the most significant bricks in England's SCG stonewall.

Stokes moved well at the squad's first session in Hobart and is expected to play as a batter.

Bairstow, who reached three figures in Sydney to register England's only hundred of the series, is a more doubtful starter after looking far from comfortable during some fielding drills on Wednesday.

"We've got to just see where they're at, see what their bodies can handle and then assess from there," Root said.

"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.

"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."

Root urged his teammates to build on the "fight and pride" they showed at the SCG and sign off the tour on a high note.