Australia vice captain Shane Watson has a left calf injury and may not bowl again in the current Test against Sri Lanka at the MCG.
Cricket Australia physiotherapist Alex Kountouris broke the news late Thursday night.
"Shane sustained a left calf injury while bowling on day one," Kountouris said.
"He was able to get though the batting innings today and is likely to field on day three.
"Whether he bowls in the second innings will be determined closer to the bowling innings.
"A decision on his availability for the New Year Test will be made after the completion of the current match."
Watson and captain Michael Clarke added 194 for Australia's fourth wicket on day two, the skipper made 106 and Watson fell in the very next over for 83.
Clarke has scored five Test hundreds in 2012 and he says the key is getting through that initial nervous period, get to 30, adjust to the bowling and conditions and then cash in.
Australia's No.4 Watson consistently gets the first part right but, with a record of 19 half-centuries and two hundreds, Watson's poor conversion rate continues to dog him.
Even worse was the manner of the dismissal on Thursday as Watson saw two fielders placed on the leg-side boundary and played a hook shot anyway.
Clarke strongly defended his vice-captain, saying that most times Watson would have scored a boundary with the shot.
Clarke is also putting his faith in what he's seen from Watson at one-day international level where he's scored six hundreds.
"It's very exciting the way Watto played. He showed a lot of discipline in his shot selection," Clarke said.
"Even the ball he got out on, as his captain, I'm not disappointed with his shot selection because he pulls and hooks as good as anybody in our team.
"Nine times out of 10, that will go for four or six. It was unfortunate today it went straight to the fielder.
"I have no doubt at all that he'll score plenty of hundreds for Australia."