Stefanos Tsitsipas cites young stars who will emerge as future rivals.
The Russians are running hot on the doubles court as well.
The 24-year-old announced the news on Instagram.
Alexander Zverev asserts ATP rankings system is absurd.
For the first time since 2005 a man not named Djokovic, Nadal, Federer or Murray is world No. 2.
"I'm going to keep pushing and see what's possible," says former world No. 1.
Patea announced the news on Instagram.
