Australia opening batsman Justin Langer is hopeful of playing in Sunday's second test against Pakistan after suffering a back injury.

"I'm still a bit sore but I have not given up hope and I guess we'll know what the form is tomorrow morning," Langer told reporters on Saturday.

Langer, suffering from a bulging disc, broke down while fielding a ball at training at Melbourne Cricket Ground on Thursday.

"There's still, I guess, doubt -- definite doubt," Australia coach John Buchanan said on Saturday.

"But he's certainly improving so we'll keep monitoring that and hopefully make a decision as early as possible -- for his sake, but also for (stand-by player) Simon Katich as well."

Langer is test cricket's leading scorer in 2004 with 1,426 runs, including five centuries.

The 34-year-old left-hander was man of the match after scoring 191 and 97 in last week's first test against Pakistan in Perth, where Australia won by 491 runs.

Langer underwent pool and massage sessions before and after the team's traditional Christmas lunch on Saturday.

Australia captain Ricky Ponting said: "A bad back is not easy to shake but if anyone can shake it, it would be Justin."