Australia coach Darren Lehmann will be judging Test aspirants Alex Doolan and Phillip Hughes in more ways than one during an intra-squad match in Johannesburg.

Lehmann and bowling coach Craig McDermott will umpire a two-day hit-out at the Wanderers, which was hastily organised after the cancellation of their only tour game in Potchefstroom due to rain.

Lehmann, speaking a day before the contest started on Friday, already had some firm thoughts on who would replace George Bailey in the side for next week’s opening Test against South Africa in Centurion.

But he said ultimately the make-up of his XI would be guided by the pitch and weather.

“I think we pretty much know what we’re going to do. It depends on what sort of wicket we’re going to get at Centurion, at the moment I can’t see it,” Lehmann said of sodden SuperSport Park.

“They (Doolan and Hughes) have both been good… both those guys will come into contention.

“There’s supposed to be some rain about as well so it could be a late call what side we play, it could be as late as the morning of the game.”

Shane Watson is expected to remain at No.3 in the batting order, but Lehmann said shifting the allrounder to No.6 was still very much a possibility.

Watson has not bowled in the nets this week, but will be right to send down some overs against the Proteas, according to Lehmann.

Hughes and potential debutant Doolan will be desperate to impress at the Wanderers before the first Test starts on Wednesday.

Lehmann wants all of his charges to treat the practice clash like it was a Test.

“As best we can. I know it’s tough in those sort of situations but if you’re out you’re out,” he said.

“We’ve got to make sure they get enough batting where possible, and get prepared for what is a pretty important series.

“We’re going to umpire … so we can talk to batters and bowlers at the same time as the game goes on.”

Rain is predicted to interrupt the contest, continuing its role as the squad’s bugbear since landing in Johannesburg over a week ago.