Australian allrounder Shane Watson remains in doubt to play in the first Ashes Test against England after an unconvincing performance at training.

Watson gave his strained right hamstring a gentle test by running laps and doing some light sprint work for 45 minutes before bowling three overs in the nets off five paces.

The 25-year-old then left training with team physiotherapist Alex Kountouris to undergo further scans on his injury.

Watson faces a race against time to prove his fitness for the start of the first Test at the Gabba, starting Thursday, despite his team's satisfaction with his progress since he was injured bowling for Queensland against Western Australia in Perth last Friday.

A Cricket Australia spokesman said Watson had ran at about 70 per cent capacity and would train with the squad on Tuesday.

Australia will reshuffle its team significantly if Watson is ruled out. As a sixth batsman, Michael Clarke will come into the side.

Watson's absence is also likely to favour NSW's Stuart Clark in the battle for the third paceman's role because of his ability to bowl long spells.

Clarke said he was preparing to play regardless of Watson's progress, but admitted he did feel for his teammate.

"There were some positive signs today, he was running around and having a bowl," Clarke said.

"It's hard, it's awkward for me right now because I do wish Watto well.

"I hope he gets well, he's worked hard over the last few months and he deserves his opportunity, so I hope he does pull up OK.

"I know the selectors will give him to Thursday to see how he pulls up."

Clark and his fast bowling rivals Mitchell Johnson and Shaun Tait today said they were unsure on what line-up Australia's selectors would pick if Watson was ruled out.

Brought to you by AAP © 2024 AAP