Roger Federer is the form player going into next week's US Open but Novak Djokovic is favourite to win the title for a second time, said former champion John McEnroe.
Federer, who reigned supreme at Flushing Meadows with five consecutive titles from 2004, won the Cincinnati title last week on the back of reaching the final in Toronto. With Rafa Nadal injured, many believe the 33-year-old Swiss maestro can claim an 18th grand slam title.
"Obviously not having to deal with (Nadal) is a huge positive for him potentially down the road if he's at a stage at the end of the event," McEnroe told ESPN.
"I would give a slight, slight favourite to Djokovic based on it being best-of-five. He's younger and he can go the distance perhaps a little bit more easily than Roger at this stage. A little bit.
"Depending on what happens leading up to it if they were to play in the final, some of it would have to do with how much was left in the tank from previous matches."
Djokovic beat Federer in an epic Wimbledon final earlier this year.
McEnroe believes Briton Andy Murray, the 2012 champion, can use the US Open to spark a long-awaited return to form, while he also tips Canada's Milos Raonic and Bulgarian Grigor Dimitrov to make strong runs on the New York cement.
Murray has not won a title since Wimbledon last year and has slipped to ninth in the world rankings, although he will be seeded eight in New York because of Nadal's wrist injury.