Defending champion Rafael Nadal has admitted that he will have to be on the top of his game if he is to beat Jack Sock in the last 16 of the French Open.
Nadal will be appearing in the fourth round of a Grand Slam event for the 33rd time in his career, whereas it is the first time that 22-year-old Sock has reached that stage of a major competition.
Despite that, Nadal is wary of the American youngster, who beat 10th seed Grigor Dimitrov earlier in the tournament.
"He's a great player. He's playing fantastic, winning very tough matches against very difficult opponents like Dimitrov, Pablo Carreno Busta, and today against Coric," the nine-time Roland Garros champion told reporters.
"He has an amazing forehand, very good serve, and then he's a player that can play very aggressive and is dangerous. I know I have to be very solid.
"I know I have to play aggressive and try to not let him hit the forehand in positions, because I am going to be in big trouble."
Nadal dropped just six games during his third-round win over Andrey Kuznetsov on Saturday.
