LONDON, SEPTEMBER 22

Novak Djokovic hailed the retiring Roger Federer as one of the greatest athletes of all time and said he would leave a lasting legacy for the world of tennis.

The 41-year-old Swiss great will play competitively for the last time at this week's Laver Cup, turning out for Team Europe alongside Rafa Nadal, Andy Murray and Djokovic - the three biggest rivals of his glittering 24-year career.

Federer, who has won 20 Grand Slam titles, has struggled with injuries in recent years and said last week that he would end his career after the Laver Cup in London. Read full story

"His impact on the game has been tremendous, the way he was playing, his style, effortless, just perfect for an eye of a tennis coach, player or just a tennis fan," Serbian Djokovic told reporters on Wednesday at London's Tower Bridge.