John McEnroe feels only four men are in with a chance of winning the US Open

It has been 20 years since Andy Roddick hoisted the trophy at Flushing Meadows and even though Frances Tiafoe, who made a thrilling run to the semis last year, and Taylor Fritz are both ranked in the top 10, the tournament favourites are simply too dominant right now in the eyes of the four-time champion.

"It's hard to envision," McEnroe said of whether anyone not named Novak Djokovic, Carlos Alcaraz, Daniil Medvedev or even Jannik Sinner could triumph.

"I'd love to see Francis get his act together and do something, but he got to the semis, so he's going to feel pressure even trying to replicate that.

"But it would be incredible for an American player to make a breakthrough to me, but the likelihood is that it isn't going to happen.

"You can see it's going to be Djokovic or Alcaraz, Medvedev is the next guy, and then Sinner. After that, it's going to be pretty tough to envision a guy going all the way."

Tiafoe's semi-final appearance, after beating Spanish great Rafa Nadal in the round of 16, elevated him to a household name, with former First Lady Michelle Obama among those who packed into his sold-out matches last year.

But the North American hard court swing following Wimbledon has been disappointing for the 25-year-old son of immigrant parents from war-torn Sierra Leone.

After making the quarters at his home tournament in Washington DC, he suffered first and second round losses in Toronto and Cincinnati.

Fritz had a slightly more fruitful summer but was mauled by Djokovic last week and has never made it past the third round in New York, including a first-round loss last year.

Ranked ninth, Fritz does have one of the most dominant serves in the game and if his primary weapon is firing, a deep run is not hard to imagine.

Tommy Paul, who beat Alcaraz at the Canadian Open, Wimbledon quarter-finalist Christopher Eubanks and Sebastian Korda are among the other American players who will look to snap the Grand Slam dry spell at the US Open, which runs from August 28 to September 10.