PERTH, Australia (AP) -- Nick Kyrgios has withdrawn from the Australian team at the Hopman Cup because of a back injury and has been replaced by Matthew Ebden.
Kyrgios, who beat Rafael Nadal in the fourth round at Wimbledon in July, also planned to play in the Sydney International before the Australian Open begins on Jan. 19 but this is now uncertain.
Ebden will be partnered by Casey Dellacqua in the Hopman Cup mixed teams event in Perth, tournament officials said Thursday.
I’m gutted to miss the Hopman Cup,” Kyrgios said on Twitter.
“He's borderline, he probably could have gone out and played [Hopman Cup], but if he had a real tough match he could wreck it and not play Sydney or the Australian Open," coach Todd Larkham told reporters.
Australia opens play on Sunday against Poland, with Canada earlier taking on Czech Republic.
Americans Serena Williams and John Isner will play their first match Monday against Italy.