John McEnroe has backed Novak Djokovic to win the US Open for his 18th Grand Slam title. The American believes the absence of Roger Federer and Rafa Nadal makes the Serb the overwhelming favorite at Flushing Meadows.While discussing Djokovic's chances of picking up a fourth US Open crown, McEnroe, a four-time champion at Flushing Meadows, told ESPN that with Federer and Nadal not in the draw, there are very few players capable of stopping the World No. 1.Novak Djokovic is playing at a level higher than we’ve ever seen: John McEnroeNovak Djokovic won the Cincinnati Masters last monthNovak Djokovic has been in great touch this year, winning the Australian Open, Dubai Duty-Free Tennis Championship and Cincinnati Masters.Novak's perfect season and Serena's bid for #24 are among the top stories of the 2020 #USOpenMen's singles preview 👉 https://t.co/9eWcmX6QXlWomen's singles preview 👉 https://t.co/YcbF399bC3 pic.twitter.com/Jwx622XFtF— US Open Tennis (@usopen) August 30, 2020He enters the US Open riding a 23-match win streak and for the first time in his career, does not have either Nadal or Federer in the draw alongside him. When asked to pick his US Open 2020 winner, John McEnroe said:"I'm definitely going with Novak [against the field]. Unfortunately, Roger [Federer] and Rafa [Nadal] aren't here and that hurts a little but, but I don't think the odds have ever been higher that [Djokovic] is going to win this."Djokovic compiled a 41-match unbeaten streak in 2011, but McEnroe believes the Serb has taken his game to an even higher level this year."The guy's playing at a level perhaps higher than we've ever seen. He doesn't have to play his two greatest rivals. He hasn't lost a single match all year," McEnroe added. Can Dominic Thiem end Djokovic's win streak?Novak Djokovic will kick off his US Open campaign against Bosnia's Damir Dzumhur and could face his first stern test against John Isner in the fourth round.A second title at @CincyTennis 🏆🏆@DjokerNole | #CInCyTENNIS pic.twitter.com/i2HGWDd6pf— US Open Tennis (@usopen) August 29, 2020If he does make it to the final, he could set up a clash with second seed Dominic Thiem, who provided the Serb with a stern test in the Australian Open final this year.