Ricky Ponting will tough it out for fourth test: Justin Langer

Australia skipper Ricky Ponting will "definitely" tough it out and play in the fourth Ashes test despite fracturing a finger in the third test victory, according to batting coach Justin Langer.

Ponting, who sustained the injury to the little finger on  his left hand while fielding on the third day of the Perth test, faces a race to be fit for the Melbourne encounter, which starts on Sunday.

"I would be amazed if Ricky doesn't play in this test, he is that tough physically and mentally," Langer told Tuesday's Sydney Morning Herald. "At one-all (in the series), Boxing Day test, a chance to win the Ashes, he will definitely be there."

Ponting, who turned 36 last Sunday, has had a disappointing series with the bat with just 83 runs at an average of 16.60, 51 of those coming as Australia batted out the first test for a draw in Brisbane.                                        

Former opener Langer, who played more than 100 tests before his retirement at the end of the 2006-07 Ashes series, said he thought the fracture might even help his former skipper.

"His injury might work in his favour," he added. "He has been trying so hard and this might help him relax and get ready for the test match. Rather than working too much and doing batting beforehand, this might be the breather he wanted."

If Ponting was unable to play, the captaincy would fall to his anointed successor, Michael Clarke, who has been equally unimpressive at the crease barring one innings of 80 in the lost Adelaide test.

Former skipper Ian Chappell said Clarke's Ashes form, which followed a poor tour of India, would place in doubt his long-term prospects of taking over as Ponting's successor.

"I'm sure Clarke will get the job in Melbourne if Ricky can't play," he told Melbourne's Herald Sun newspaper.

"But it's a different question if you're asking about permanent captaincy with Michael Clarke.

"That's where the area becomes really clouded because the England bowlers have sorted him out a bit with some short-pitched stuff.

"The last thing you need to do is appoint a long-term captain when he's got a bit of a problem with short-pitched bowling," Chappell added.

"Clarke has got to answer those questions as a batsman before he gets back to that position of being undoubtedly the replacement for Ricky Ponting."

Usman Khawaja was put on stand-by on Tuesday and will make his test debut in Melbourne should Ponting be unable to bat.

"While (we) are confident Ricky Ponting will be available for the Boxing Day Test, through an abundance of caution we have named Usman Khawaja as the standby player," chief selector Andrew Hilditch said in a Cricket Australia statement.

"Usman richly deserves this opportunity following his excellent form at domestic level last season and continuing on  this season."

Free-scoring lefthander Khawaja had already said he was  ready for the call.

"I've said this before, I think I was ready when I was six years old," the 24-year-old told reporters on Monday. "I think everyone's ready to play for Australia."