That is the view of world No 6 Kei Nishikori.
Nadal is in Monte Carlo for his first event since last month’s Masters 1000 tournament in Indian Wells where he was forced to withdraw from the semi-finals due to injury.
The Spaniard has spent the past few weeks recuperating and is back to full fitness as he aims to win a 12th Monte Carlo title.
Nadal is unquestionably the best player to ever play on clay and it means he enters every event on the surface as the man to beat.
In an interview with the ATP, Nishikori was asked what it takes to beat Nadal on clay and the Japanese star replied: “Rafa is the best player on the clay.
“But I think this surface is a little bit slower and [you] have a little bit more time.
“His spin will be heavy on his surface and I think it suits his game a lot.
“[It’s] not easy to beat Rafa on clay of course but also here in Monte Carlo.”
Nishikori’s comments were echoed by world No 1 and top seed Novak Djokovic.
The Serbian struggled in March, suffering surprising defeats in Indian Wells and Miami.
And he knows Nadal is still the best, especially if he is healthy.
“I think Rafa is always a very clear favorite on any clay court in the world, and it doesn’t change,” Djokovic said.
“He’s still there. I mean (it) obviously depends how he’s feeling physically.
“I have seen him (training) here, he’s been here a few days. Seems like he’s fine.”
“Obviously clay is a completely different surface. It’s very demanding physically, tactically, you have to be more patient, resilient, more enduring
“You have to be able to construct the point in various ways. It is a slow surface.
“[The] clay courts here in Monaco are probably the slowest of the big ones that we have on the Tour.
“My game and everybody’s game will be tested big-time, but that’s why we’re here.”