A blow to the arm could dent the chances of Australian opener Joe Burns being selected for the Boxing Day test against the West Indies.
Burns suffered the injury scare in the nets but did return to complete the session.
He faces pressure from Usman Khawaja, who lost his place thanks to a hamstring injury suffered against the Blackcaps.
Opening batsman David Warner says he isn't fussed on who is selected though.
Burns admits he's in line to be dropped, after notching a maiden century in the first test against New Zealand - he hasn't passed 50 in his last five innings.