Novak Djokovic admits he is concerned by his performance levels this season ahead of launching his title defence at the French Open.

The world number one's wait for his first silverware of 2024 continued following a semi-final defeat by Tomas Machac in Geneva on Friday.

He also fell in the last four in Melbourne and Monte Carlo, while suffering a shock defeat at the hands of world number 123 Luca Nardi in the last 32 at Indian Wells.

Therefore Djokovic, who split from long-term coach Goran Ivanisevic earlier in the campaign, can be forgiven for not being full of confidence ahead of his latest quest for a record-breaking 25th grand slam singles title at Roland Garros.

"Of course, I am worried. I haven't been playing well at all this year," he said after his defeat to Machac.

"It's not enjoyment when you are suffering on the court feeling this way. You're not able to focus on tennis when you have other stuff happening. I just hope I can be fit and ready and prepared for Roland Garros.

"I don't want to take anything away from his win, he deserved it. I don't know what to think about this match, to be honest. I want to forget about it and move on to Paris.

"It was good that I could come here and play more than one match. I played three. I just need to feel better."

Djokovic will become the fourth man in the Open Era to make 20 or more main-draw appearances at the French Open when he begins his campaign against local wildcard Pierre-Hugues Herbert.

A run to the quarter-finals at Roland Garros - without walkovers - would see him surpass Roger Federer for the most singles match wins at majors.

Although, an early exit could see the 37-year-old surrender top spot in the ATP rankings, with world number two and reigning Australian Open champion Jannik Sinner breathing down his neck. 

"[I've had] some [good] matches here and there, but it is what it is," he added. "You have to accept it. I don't consider myself a favourite there. I'm going to take it match by match and see how far I can go."