Not only is Shane Watson fit again, he's fitter than he ever was during the Australian summer.

Watson faces a final test today but the all-rounder is confident he'll be ready for the Test series decider against South Africa.

Selectors have yet to declare their intent but Watson shapes as a likely inclusion given the side's batting woes and overworked bowlers in the Second Test loss in Port Elizabeth.

Watson, who recovered from a persistent calf injury, will hold nothing back when Australia have their one and only training session before the third Test starts in Cape Town on Saturday.

The 32-year-old, told he needs to bowl to warrant national selection, sent down five overs of medium pace off a full run-up in the nets on Monday.

"Next time I bowl on Thursday I'll be bowling at match intensity," he said.

"I have to bowl one more time to be declared fit to play and then it is up to the selectors.

"I shouldn't have any problems about getting through another bowling session."

Watson described his latest setback as frustrating but noted that the unwanted time off had been of major benefit.

"It gave me a chance to get my body right," he said.

"I obviously had a few niggles during the summer I played with. It [not rushing back and playing the Second Test as a batsman] actually worked out better because when I come back this time those niggles will have gone away."

Watson had no idea where he would bat if asked; he was just as happy at No 6 as No 3.

"I've been able to bat in all different positions through my career, so I'll be able to adapt quickly."

The star all-rounder was also in the dark about how many overs he'd be called on to bowl, if selected.

Watson has form at Newlands - he took 5-15 from five overs in 2011 - but given the collapse that followed it's a match he tried to erase from his memory.

"It'd be nice if that happened again and the conditions were the same. But not the back part of that [Test]," he said, of the game where Australia were skittled for 47 on the way to an eight-wicket loss.

"The wicket has normally got a bit of seam and swing in it for the first couple of days. I know if I'm fit and get picked that my bowling could be suited to it." AAP