Kyrgios pulls out of Oz Open warm-up with knee injury

Controversial Australian tennis star Nick Kyrgios, in a setback to his Australian Open, has pulled out of a World Tennis Challenge exhibition in Adelaide after suffering from a knee injury.

"Unfortunately I am unable to play @WTCAdelaide this year. I have to rest & do all I can to be ready for #AO17 but I will be back next year," Kyrgios said on Twitter.

The 21-year-old, who reportedly damaged his left knee while playing basketball, is receiving treatment and then will rest in the lead-up to the opening Grand Slam of the year starting on Monday in Melbourne, reports Sport24.

The World No. 14 has struggled with the issue during a straight-sets defeat against American Jack Sock in last week's Hopman Cup.