Australian golfer Jason Day has withdrawn from the Masters with a left leg injury midway through the second round.

Day battled through seven and a half holes on Friday before finally calling it quits with his strained ankle ligament causing too much discomfort.

Having injured himself in training last week Day was hopeful he could get through the tournament, but after wincing in pain on the second hole the 24-year-old was noticeably hobbled.

Day was one-over on his round and five-over for the tournament at the time of withdrawal.

It was another blow to the Australian tilt, which is fading.

Not so for Northern Irishman Rory McIlroy, Spaniard Sergio Garcia and Americans Jason Dufner and Fred Couples who hold the lead at five-under par.

Dufner and former champion Couples carded a two-under par 70 while McIlroy, Garcia still have holes to play.

Tiger Woods has two early birdies but also a bogey to be tied 18th at one-under par.

Aaron Baddeley (10 holes) leads a stumbling Australian tilt but at even par he sits a little off the pace.

Baddeley started with an unlucky bogey but rebounded with back-to-back birdies to be at two under and just three off the lead at the time.

The Victorian then made a clever up and down from the bunker on the fourth to stay right amongst it before trouble struck on the fifth.

The 31-year-old blocked his tee ball into dense forest on the right and was forced to re-tee.

He then found bunker trouble and missed a short putt leaving him with a triple bogey.

Another bogey at the seventh was tempered by birdies at the eighth and 10th holes.

Adam Scott is a shot further back at one-over par through 11 holes while Geoff Ogilvy is at two-over through eight.

John Senden posted a 76 early to drop to six-over par for the tournament, ending his Masters assault and amateur Bryden Macpherson needs a miracle to continue as he is 10-over par with just six holes to play.

The top 44 and ties plus anyone within 10 shots of the lead make the weekend.