PARIS • Tennis at the Olympics should be treated like a fifth grand slam and ranking points awarded, said Novak Djokovic after top American John Isner confirmed he would skip the Games in Rio de Janeiro.

With no agreement in place between the International Tennis Federation (ITF) and the two Tours, the ATP and WTA, no points will be available for those players competing for medals at the Games which start in August.

World No. 17 Isner said that was a pivotal factor in his decision not to play in Brazil.

World No. 1 Djokovic will compete in Rio, but he has some sympathy for the American.

"That was one of the debates, I think, whether or not we should have points in the Olympic Games," Djokovic told reporters after his first-round win against Chinese Taipei's Lu Yen-hsun at the French Open on Tuesday.

"To be quite frank, I don't see a reason why not. You know, we have the best players in the world participating in arguably the fifth Grand Slam. It's of that importance for all of us, even more, because it happens every four years," added the Serb ahead of his second round clash with Steve Darcis.

"I would definitely encourage people to rethink (the issue) of getting points out there."

Isner is not the only player to turn down the Olympics, where Andy Murray and Serena Williams will be defending their singles titles.

Rising Austrian Dominic Thiem, Australian Bernard Tomic and veteran Spaniard Feliciano Lopez will all be absent.

Isner said the schedule had worked against him, since the US Open comes shortly after Rio and the Davis Cup quarter-finals just after Wimbledon. But the lack of ranking points had convinced him.

"I think the fact that they have no points, to be honest, was a pretty big factor," Isner said after beating Australian John Millman in the first round of the French Open on Tuesday. "Obviously the Olympics is not about the money, but no points, I think, hindered me a bit."

REUTERS