Michael Clarke doubtful for Boxing Day Test

Australia skipper Michael Clarke is a fitness doubt for the Boxing Day Test with Sri Lanka in Melbourne.

The middle-order batsman picked up a hamstring injury in the 137-run first Test victory over the tourists in Hobart.

Coach Mickey Arthur is determined to give Clarke as much time recovery time as possible before making a decision, but does have contingency plans in place.

Usman Khawaja is on standby to replace the 31-year-old in the XI, with Shane Watson poised to take over the captaincy.

Uncapped paceman Jackson Bird is in line for his Test debut, with seamers Ben Hilfenhaus James Pattinson, Ryan Harris and Pat Cummins all sidelined.