Patrick Mouratoglou has completely played down the chances of Serena Williams winning the French Open, but says her time will come to win a 24th grand slam title.
Williams will head to the French Open still trailing Margaret Court's all-time majors record by one, having gone over four years without winning a grand slam.
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Roland Garros has been the least rewarding of the four grand slams for Williams, a stat that isn't filling her coach with confidence.
The 39-year-old won the last of her 23 grand slam singles titles at the Australian Open in 2017.
She has since lost four grand slam finals and hasn't been past the fourth round at Roland Garros since 2016.
"Since 2018 she played grand slam finals on all surfaces other than clay," said Mouratoglou, who has been working with the former World No.1 since 2012.
"When you are playing grand slam finals you're not that far from winning it.
"Of course, the last match is always the most difficult. There is this pressure when you play a match for history that you have to be able to handle.
"I would say that Roland Garros is the most difficult because it requires her to be at the top on the physical side and it doesn't highlight her qualities in the same way.
"But I think on the other surfaces she will have her chance."
Serena Williams' struggles on clay
Three of Williams' majors have come in Paris but her strong serve and big groundstrokes are blunted by the slowness of the clay-courts.
She will go into the French Open with just a single win on clay this season - against 17-year-old Italian Lisa Pigato, ranked 512th in the world.
But Mouratoglou stressed the American rarely plays many events before a grand slam.
"If I answer you today I am not going to rate her chances really high because she's lost the second round in the last tournament, and first round the one before," the Frenchman said.
"So it's difficult to say that she's going to win Roland Garros.
"But we still have 10 days to work so we got to take the best out of those 10 days and I know how much work she can do in a short period of time and how much she can improve."
Williams has been training at Mouratoglou's academy in Nice, which will also host eight of the top ATP players including Daniil Medvedev and Diego Schwartzman for the fourth edition of the Ultimate Tennis Showdown (UTS) from Monday.
Grigor Dimitrov, Cristian Garin, Fabio Fognini, Taylor Fritz, Alexander Bublik and Corentin Moutet will complete the line-up for the two-day event.
Started during the 2020 shutdown, UTS, co-owned by Mouratoglou and previously attended by the likes of Dominic Thiem and Stefanos Tsitsipas, is played in a format like the tie-breaker in traditional tennis with each player having two serves in a row.
The upcoming edition will see players having only one serve and each match will consist of four eight-minute quarters.
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