PARIS, May 28, 2024 (BSS/AFP) - Novak Djokovic begins the defence of his French Open title on Tuesday, confident his Grand Slam pedigree will help overcome his lacklustre season.

The world number one, seeking a fourth Roland Garros title and record-extending 25th major, is enduring his worst run since 2018.

Djokovic, 37, has not won a title in 2024 and has yet to make a final with semi-final spots at the Australian Open and Monte Carlo Masters remaining his best performances.

He also suffered the indignity of being accidentally hit on the head by a metal water bottle in Rome which caused nausea and dizziness.

In Geneva last week, where he was knocked out by Tomas Machac of the Czech Republic, Djokovic said he had been suffering from a stomach problem.

"I wouldn't call them holes. They are rather bumps on the road," said Djokovic, who watched his long-time rival and 14-time champion Rafael Nadal bow out of the tournament against Alexander Zverev on Monday.

"I have always looked ahead, what is the next challenge, and what it takes for me to be better than I was last week."

When asked to elaborate on his difficulties so far this season, Djokovic opted for discretion.

"Various things have been happening in the last couple of months, but I don't want to get into it. I don't want to open Pandora's Box.

"What has happened, happened, and it's in the past.

"I know exactly what I need to do in a Grand Slam environment. I've experienced that 24 times in my career."

On Tuesday, Djokovic will take on French wildcard Pierre-Hugues Herbert who he defeated in their only other previous meeting at the Paris Masters in 2013.

Herbert, the world number 142, made the third round in 2018 but hasn't won a match on the main tour this year.

Elsewhere on Tuesday, two-time Australian Open champion Aryna Sabalenka gets her bid to reach a first Roland Garros final underway.

The world number two has reached at least the semi-finals in each of the past six Grand Slam events.

Sabalenka is also the only woman to beat world number one and three-time French Open winner Iga Swiatek in a final on clay -- in Madrid last year -- since the Pole lost her first WTA title decider as a teenager in 2019 at a low-key event in Switzerland.

The 26-year-old Sabalenka had never even reached the second week at Roland Garros until last year, when she was knocked out by Karolina Muchova in the semi-finals.

"Iga definitely motivates me a lot to get better, and I think I improve so many things just because of her. She kind of like pointed to the things I wasn't good at," said Sabalenka who starts her Paris campaign against Russia's Erika Andreeva.

Fourth seed Elena Rybakina, whose best run at Roland Garros was a quarter-final spot in 2021, tackles Greet Minnen of Belgium.

Also on court in the men's singles on Tuesday is Argentine qualifier Roman Andres Burruchaga who has sporting success in the blood.

His father Jorge famously scored the winning goal for Diego Maradona's Argentina in the 1986 World Cup final against West Germany.

Ranked at 144, the 22-year-old is making his Grand Slam debut and takes on Germany's Jan-Lennard Struff.