Australia have added left-handed batsman Rob Quiney to their squad as cover for all-rounder Shane Watson for the first test against South Africa.
Watson injured his calf playing for New South Wales against Queensland on Saturday and is a doubt for the test, which begins on Friday at the Gabba in Brisbane.
"A decision on Shane is likely to be made earlier rather than later," national selector John Inverarity said in a statement on Sunday.
Former skipper Ricky Ponting is also recovering from a hamstring niggle.
Victorian opener Quiney scored 85 in a practice match against South Africa to stay on course for a potential test debut against the world's top-ranked side.
"His 85 from 113 balls against the strong South African attack demonstrated a good range of shots and a sound technique," Inverarity said.
"He is in good shape at the moment and he is ready to grasp his opportunity should he get the nod for Friday."
Quiney said he was up for the challenge of taking on South Africa's formidable pace attack, which is led by Dale Steyn.
"Hopefully Shane can get up and be right because he's such an important player for the team but I'll obviously be training and preparing to be ready to go if he doesn't get up," said the 30-year-old.