Making such comparisons is very hard because it's not an exact science. While all sports are respectable, they're not created equal, and individual ones like tennis carry more weight because players are all alone on the battlefield.
Not all can handle that, and there is some safety in playing team sports. Novak Djokovic doesn't mind as much as he proved it this year for the 'nth' time by winning three of the four Grand Slams. His last one came in New York, a sensational performance against Daniil Medvedev in the US Open final to win his 24th Grand Slam.
That was just amazing to Rusedski, who proclaimed him the best athlete on the planet right now during a recent appearance on the Inside-In podcast.
Novak to me is the best athlete on the planet at the moment bar any sport. I don't care what sport you are talking about. His consistency, what he is doing on court and what he is doing at his age, nobody has done before apart from Tom Brady with the Super Bowl wins.
If he's the best athlete on the planet, it's obvious that by extension Rusedski finds him the best tennis player on the planet as well. He's the GOAT according to the former player.
Right now I'd say he's the GOAT, wanting 27, 28 Majors and distancing himself from the pack. He's tied Margaret Court with . Not only he wants to be the best male tennis player, he wants to be the best tennis player male, female, anything. An Olympic gold next year in Paris is huge for Novak.