The mind is willing for Thanasi Kokkinakis but the body isn't with the promising Australian again frustrated by injury.
Returning to Melbourne Park for the first time since 2015 after undergoing shoulder surgery, the 21-year-old had his Australian Open cut short by rising Russian star Daniil Medvedev on Tuesday.
An inconsistent Kokkinakis pushed hard but was unable to match the Sydney International champion, falling 6-2 6-7 (6-8) 7-6 (10-8) 6-4.
It was a second blow for local fans by Medvedev, who beat another young Australian Alex de Minaur in the final at Homebush last week.
Kokkinakis had to call for medical treatment on his calf and his pectoral muscle telling the trainer his body was a "shambles", although post-match he felt the chest problem wasn't serious.
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"I felt really good going out there and then just as it was going on, I started to feel a few things," Kokkinakis said.
"I tried to shorten the points a little but it's pretty frustrating.
"At the moment when I'm playing long matches, I'm trying to peak for certain moments because I don't feel like I can put my best in every point I'm into and that's why I think there's so many ups and downs in my matches."
Kokkinakis looked in control of the third set tiebreak, racing to a 3-0 lead but the Russian reeled off the next six points.
Kokkinakis then saved four set points including three in a row with both players sending down some cracking winners.
But world No.53 Medvedev wouldn't be denied, with his lethal backhand sealing the set.
He then broke early in the fourth and rumbled down an ace on his first match point.
Kokkinakis said he knew it would be tough to overcome the battle-hardened Russian once he lost that third set.
"He's obviously played a lot more matches the past couple years and he's playing some good tennis right now."
The South Australian said more matches was what his body needed so he could make a real dent in the grand slam draws.
"I have to stay on the court, keep working, play some more matches and more tournaments.
"Hopefully by then, by the next sort of slam that rolls around, I'm in better shape.
Medvedev will next face South Korean Hyeon Chung.
