The ATP 500 Basel event is less than six months away but the best players in the field are already known.

Roger Federer & Rafael Nadal, the two great rivals of Tennis
Roger Federer & Rafael Nadal, the two great rivals of Tennis

As the tickets go on sale from today, the tournament announced that Roger Federer, who is in contract with the event until 2019, world no. 3 Stan Wawrinka, world no. 5 Rafael Nadal and world no. 16 Nick Kyrgios will be playing in the event.

Last year Roger and Nadal could not play due to injury, while Kyrgios was banned for three weeks. Nishikori is expected to be there, said by Sergio Palmieri, who is one of the organizers of this tournament last year.