Melbourne: Former semi-finalist Marin Cilic has ruled himself out of this year's Australian Open, tournament director Craig Tiley confirmed on Saturday.

The 23-year-old Croatian, beaten in the last four by Briton Andy Murray in 2010, had not recovered from a knee injury, Tiley said in a post on his Twitter account.

"Just got word Marin Cilic has had to withdraw from the Australian Open as he is not ready after his knee injury," Tiley said.