Published: Dec 13, 2011 6:30 AM EST
Updated: Dec 13, 2011 7:31 AM EST

MELBOURNE, Australia (AP) - Defending champion Stuart Appleby is in doubt for this week's Australian Masters due to a nagging back injury.

Appleby said Tuesday that his back had become so painful it had ruined his swing and made practice difficult. He said he hoped rest and treatment over the next two days would enable him to tee off Thursday at the Victoria Golf Club, but may need to withdraw.

Appleby said he doesn't know his body well enough to know whether he can make do with an ad hoc swing "or whether it's a futile fight that I need to try another day," adding "I'll make that decision closer to the time."