The 23-year-old is coming up the rankings quickly this year.
The Czech teen is the fifth-youngest quarterfinalist in event history.
The Russian doesn't want the public knowing everything about his life.
The Czech has won eight straight matches at the Masters events.
"I'm a fan of the electronic line calling, but the ball was...like four, five centimeters [out]," Alexander Zverev said.
"I'm not sure if I will come back," Novak Djokovic said after his loss to Matteo Arnaldi today.
The American has zero points to defend through Roland-Garros.
