Australia's men's number one tennis player Nick Kyrgios doubts he will be at his best for the Australian Open, which starts next week.
Kyrgios, 19, said he was "shattered" and had not had "the right preparation" as he lost to Poland's Jerzy Janowicz at the Sydney International on Tuesday.
The 6-1 6-7 (6-8) 7-6 (7-5) defeat was Kyrgios's first match after four months out recovering from injury and fatigue.
He said he could "only do so much" for the Australian Open.
"We'll see how it goes," the Australian Associated Press quoted him as saying.
"I am just doing whatever I can to get out there and compete but I am not at the level I would like to be at."
Kyrgios seemed to have been troubled by his left knee and back during his defeat by Janowicz.
The Australian defeated Rafael Nadal at Wimbledon last year and has been tipped as a future champion.