SHANE Watson laboured through his longest innings in more than two years with an injured calf, and is expected to be ruled out of the final Test in Sydney.
The injury-plagued all-rounder strained the muscle while bowling in the first innings of the Boxing Day Test against Sri Lanka, when he managed just three overs, having bowled himself into the danger zone for injury with a career-high 47.4 overs in Hobart.
But Cricket Australia nursed him through to the second Test rather than rest him for Melbourne, where he was in line to captain the side if Michael Clarke had failed to recover from a hamstring injury.
Instead, Watson combined with Clarke for a record MCG stand of 194 runs for the fourth wicket, despite the injury.
Cricket Australia said on Thursday night that the extent of Watson's injury was not yet known, and that he would field in the second innings.
He might even be able to bowl, but is almost certain to miss the third Test, given his history and the likelihood the match will be a dead rubber.
His breakdown, having also missed the first two Tests against South Africa, continues a horrendous injury run for Australia, with fast bowlers Ben Hilfenhaus, James Pattinson, Pat Cummins, Josh Hazlewood and John Hastings all sidelined.
Watson batted for 265 minutes in the Boxing Day Test, his longest innings since the most recent of his two Test centuries in Mohali in October 2010.
Among all the Australians who have made at least one Test century, only one - the former captain, all-rounder and Australian cricket Hall of Famer Monty Noble - has a worse ratio of 50s to centuries than Watson. Noble made his only Test century in 42 matches at No. 4 at the SCG in 1903, and passed 50 on 17 occasions.
Before this Boxing Day Test, Australia's new No. 4 had ventured beyond the 50 mark 21 times in 37 matches, for just two Test centuries.
He had a chance to break the trend against a depleted Sri Lankan attack at the scene of his maiden Test ton against Pakistan three years ago.
On Thursday, Watson struck eight fours and walked at Rangana Herath and clipped him for a straight six.
But after passing 50, he lumbered between the wickets and appeared to invest all his emotional energy in trying not to get out when he was set.
That was until he fell into the trap of hooking Dhammika Prasad to deep square leg soon after Clarke departed for his fifth century in this remarkable year for the Australian captain. Though it's no disgrace to make 83 and be overshadowed by a captain in the form of his life, especially under the duress of injury, Watson has now gone 33 innings without a Test century.
The vice-captain remains an integral figure in Australian cricket on account of his ability to bat in the top six and provide Clarke with a fifth bowling option. In that respect Watson is a key member of the reconfigured top order, as well as an important fifth-bowling option for Clarke. He might not be making centuries, but he is still making meaningful contributions.
But everyone, Watson included, wants more from the 31-year-old cricketer who has won two Allan Border Medals, has dominated the shorter formats and is Australia's second-highest paid cricketer.
Clarke praised Watson's discipline on Thursday night, while Watson has previously described his poor conversion rate as his ''biggest downfall'' in Test cricket.
''That's the thing I've been really looking deep inside myself to be able to find the reasons why I haven't been able to convert those decent days into those really big and good days,'' he said before the season, and before the first calf injury halted his momentum. ''And they are the innings that really influence a game.''