Roger Federer, Rafael Nadal and Novak Djokovic are all in contention for being dubbed the greatest tennis player to walk the Earth, and one coach who has played with all three has had his say

Former world No.1 and U.S. Open champion Dominic Thiem will retire at the Vienna Open later this month and tennis' biggest names have sent heartfelt messages.

Dominic Thiem turned emotional as he received best wishes from Rafael Nadal, Novak Djokovic and Roger Federer ahead of his retirement.

Roger Federer led the emotional tributes to Dominic Thiem as he prepares to retire on home turf later this month. The Austrian will put down his racket after the Vienna Open, five months after announcing that this season will be his last as a professional.