Del Potro joins Gasquet, Murray in withdrawing from Australian Open

2009 US Open champion Juan Martin del Potro is sidelined for the Australian Open due to ongoing knee issues.

The unlucky Argentine is still striving to recover from a kneecap fracture suffered at Queen's Club last June. He joins Richard Gasquet - who is also dealing with a knee problem - Andy Murray, and Kei Nishikori in withdrawing from the men's singles event.

Del Potro, 31, reached the quarterfinals of the Australian Open in 2009 and 2012.