Young Australian tennis star Nick Kyrgios has been forced to withdraw from the Hopman Cup because of a back injury.

The teenager, who eliminated Rafael Nadal at Wimbledon, will be replaced by Matthew Ebden.

Hopman Cup organisers tweeted the bad news late on New Year's Eve.

Kyrgios tweeted he was "gutted" to miss the tournament but wished Ebden and Casey Dellacqua well.

Injury-free for the first time since charging into the Wimbledon quarter-finals in July, Kyrgios was set to launch his 2015 campaign at the Hopman Cup in Perth from January 4.

Following the tournament, the 19-year-old Newcombe Medallist planned to contest the Sydney International before joining the world's best at the Australian Open in Melbourne from January 19.

AAP