A chronic hip injury threatens to cruel Nick Kyrgios's Wimbledon campaign before it even begins.
Australia's top title hope has revealed he is not even three-quarters fit ahead of his tournament opener on Monday against Frenchman Pierre-Hugues Herbert.
"Probably 60, 65 per cent," he said glumly after pulling up sore from his second win in three days at an exhibition event in Buckinghamshire.
"It's not great. I played a couple of matches at Boodles the last couple of days to see where I was at and it's definitely not 100 per cent.
"But I'm still going to obviously feel confident on the grass. I can serve well and still be successful but, at the same time, it's not where I'd like my body to be."
The injury - which he said affects "virtually everything" in his game - has been troubling the world No.20 since before he retired hurt midway through his third-round match at last year's US Open.
It also undermined his French Open campaign.
"I didn't play hard at all at the Boodles," Kyrgios said.
"I think that's why I wanted to play there. It's a very controlled environment. Both players sort of know you just want to feel the ball, you don't want to go too hard.
"I'll be doing absolutely everything I can. I've been taking anti-inflammatories, doing an hour and a half of rehab every day, getting treatment."
The 22-year-old admits long-term he will probably require surgery, as Lleyton Hewitt and Bernard Tomic have had to repair similar hip flexor issues.
"But you can avoid it if you do the right things," he said.
"I was doing everything perfect after Paris. I was in the right spot. I wasn't feeling it at all."
Kyrgios is among four Australians in action on the opening day of the 13st championships.
John Millman faces a titanic struggle but gives himself a shot of upsetting two-time champion and newly-crowned 10-times French Open winner Rafael Nadal.
"I've got a lot of respect for him but when I go on court, it's zero all," Millman said.
"And it would be disrespectful if when I go out there, I've already lost, especially at a place like this at Wimbledon where a lot of people would give their eye teeth to play."
Qualifier Andrew Whittington takes on Brazil's world No.98 Thiago Monteiro in his Wimbledon main-draw singles debut, while Ashleigh Barty plays women's fourth seed Elina Svitolina.
Svitolina is a former junior finalist at the All England Club - but Barty can boast one better, lifting the girls' trophy in 2011 and fancies her prospects of springing an early upset in the wide open women's event.
AUSSIES IN ACTION ON DAY ONE OF WIMBLEDON ON MONDAY (prefix denotes seeding):
Men's singles, first round
20-Nick Kyrgios v Pierre-Hugues Herbert (FRA)
John Millman v 4-Rafael Nadal (ESP)
Andrew Whittington v Thiago Monteiro (BRA)
Women's singles, first round
Ashleigh Barty v 4-Elina Svitolina (UKR).