Novak Djokovic's bid for a 'Golden Slam' is in doubt after the Wimbledon champion said he was "50-50" about whether to go to the Tokyo Olympics.

If he was to win Olympic gold and then the US Open title, he would become the first man to complete a 'Golden Slam'.

"I'll have to think about it," Serb Djokovic said of his Olympic plans.

Germany's Steffi Graf is the only player to complete a 'Golden Slam', which she achieved in 1988.

Djokovic had always planned to go to Tokyo but the fact it was announced last week that fans would not be allowed to attend because of a spike in coronavirus infections has affected his thinking.

"That was really disappointing to hear," he said. "I also hear that there's going to be a lot of restrictions within the [athletes'] village. Possibly you would not be able to see other athletes perform live.

"I can't even have my stringer that is very important part of my team. I'm limited with the amount of people I can take in my team as well.

"Right now I'm a little bit divided. It's kind of 50-50 because of what I heard in the last couple days."

With his latest Wimbledon victory - his sixth at the All England Club - Djokovic equalled Roger Federer and Rafael Nadal's record of 20 men's Grand Slam titles.

Further discussions among fans, pundits and the media will inevitably follow about which of these three players will end up their careers with the most major titles, whether any of them will overtake Margaret Court's all-time record of 24 Grand Slam singles titles, and who deserves the title of the greatest of all time.

Djokovic has his own views.

"I consider myself best and I believe that I am the best, otherwise I wouldn't be talking confidently about winning Slams and making history," he said.

"But whether I'm the greatest of all time or not, I leave that debate to other people. I said before that it's very difficult to compare the eras of tennis. We have different racquets, technology, balls, courts.

"It's just completely different conditions that we're playing in, so it's very hard to compare tennis, say, from 50 years ago to today. But I am extremely honoured to definitely be part of the conversation.

"I feel like I'm probably the most complete that I've been as a player right now in my entire career."