Tennis weather gods not smiling on Demon in New York

New York's lousy weather is threatening to plunge Alex de Minaur's US Open title hopes into turmoil.

Just when fans thought the tennis gods were smiling on de Minaur, unreliable weather in the Big Apple has left Australia's great white hope needing to win seven best-of-five-set matches in 12 days.

The postponement of de Minaur's first-round encounter with Italian qualifier Andrea Guerrieri to Wednesday (Thursday AEST) has left the sixth seed at the mercy of a scheduling backlog.Already among the handful of heavyweights asked to start their tournaments at the latest possible time late on day three, de Minaur's best scenario now is a rain-free run through to the weekend finals at the fourth and final grand slam of the year.

But, despite the withdrawal of his Italian nemesis and injured world No.1 Jannik Sinner, already the odds are stacked against de Minaur.

The ATP Tour's Masters 1000 events are all held over two weeks also but matches are contested as best-of-three sets.

Grand slams are now the only tournaments on the tennis calendar fought out over best-of-five-set encounters.

One of the fittest players on tour, de Minaur is considered somewhat of a tennis ironman.

But the 27-year-old is yet to even win a Masters 1000 tournament, let alone reach a grand slam semi-final.

Weather permitting, the world No.7 and three-time US Open quarter-finalist will open his 10th Flushing Meadows campaign in the second match on Court 11 on day four.

He was slated to play on the much bigger Grandstand show court on day three.

De Minaur, the nation's women's No.1 Daria Kasatkina, along with young guns Maya Joint and Taylah Preston and Kim Birrell are among five Australians scheduled for day-four action.