Patrick Mouratoglou has compared Rafael Nadal to a runaway train and thinks it may be an "impossible mission" to stop the legendary Spaniard from making history at the French Open this weekend.
Nadal has been in a class of his own on clay this year, losing only one of 23 matches on his favourite surface.
The 'King of Clay' goes marching into the semi-finals without dropping a set in Paris, where he is aiming to become the first man to win the same grand slam 10 times in the Open Era.
Nadal will face Dominic Thiem - the only man to beat him on the red stuff this season - in the last four at Roland Garros on Friday.
And Mouratoglou, coach of the great Serena Williams, cannot see anyone stopping the legendary Spaniard from completing 'La Decima'.
He told Omnisport: "I think it is impossible not to see Nadal winning it. I would be surprised with anybody who says someone else will win it.
"I think the level he's playing at, with such confidence he has generated from this season, is incredible.
"I compare it to a train at full speed; if you want to stop the train you have to stop it at the start, but nobody stopped him in the first tournaments on clay.
"Novak [Djokovic] could not stop him, Andy [Murray] could not stop him and now it's an almost impossible mission."
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