Novak Djokovic admitted he simply "ran out of gas" in his shock loss at the Monte Carlo Masters, painting a worrying outlook for the World No.1's prospects for the remainder of the season.
In just his fourth match of 2022, Djokovic succumbed to Alejandro Davidovich Fokina 3-6 7-6(5) 6-1.
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The Serbian star hadn't played since making the quarter-finals in Dubai in February in his only other tournament this year.
He was deported from Australia and unable to defend his Australian Open title in January because he refuses to get vaccinated against Covid-19.
He then missed big tournaments at Indian Wells and Miami because of a vaccination mandate in the United States, but was allowed to play in Monaco after rules were recently relaxed.
But on Tuesday, Djokovic's performance was one of a man who hadn't played a competitive match in two months.
The 20-time grand slam champion made 51 unforced errors and had his serve broken nine times - the first time that has happened in his whole career.
"I was hanging on the ropes the entire match. I was really chasing the result constantly," Djokovic said after the loss.
"I didn't like the way I felt physically in the third (set). I just ran out of gas completely.
"Just couldn't really stay in the rally with him. If you can't stay in the rally, not feeling your legs on the clay, it's mission impossible."
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Djokovic admitted his absence from most events this year had been "difficult, mentally and emotionally", but said he was "moving on" ahead of his return to the tour.
The World No.1 will be allowed to play the French Open in May, but his status for Wimbledon and the US Open is still up in the air.
After struggling so mightily in Monte Carlo it's hard to see how he will be able to string together any sort of consistent play in order to keep his No.1 ranking and add to his grand slam total.
Rafa Nadal won the Australian Open in Djokovic's absence to move one ahead of Djokovic and Roger Federer with his 21st grand slam title.
The Spaniard will almost certainly be the favourite to make it 22 at Roland Garros.
"I always believed that I could come back and win the match, and I stayed there even though a lot of things were against me in terms of how I felt on the court," Djokovic said on Tuesday.
"Game-wise, physically I was just far from my best.
"Of course in those types of conditions and circumstances, then you have to really work two times more than you normally would.
"I expected this match to be a really tough match, a physical battle, and that's what it was. Unfortunately I'm on the shorter end of the stick, and my week ends here."
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It marked the first time Djokovic had lost his opening match at a tournament since falling to Martin Klizan in Barcelona in 2018.
He hasn't been able to make it past the quarter-finals in Monte Carlo since 2015.
"I knew a few days ago when I spoke to you that it's going to take some time for me to really feel my best on the clay," he added.
"That's historically always been the case. I have never played very well in the opening tournaments of the clay season.
"But it's okay. Obviously it is what it is. I have to accept the defeat and keep working."
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