Britain's Andy Murray must wait until the night session of day three to begin his US Open title defence - and hope the weather does not intervene.
The Wimbledon champion's opening match against Michael Llodra will begin Wednesday's night session at 7pm local time [00:00 BST, Thursday].
And with the forecast suggesting thunderstorms will threaten New York, the Scot faces the prospect of going into day four having not completed his first match.
Fellow Briton Laura Robson will play France's Caroline Garcia in the second round on Wednesday, with their match scheduled second on Court 11 at around 13:00 (18:00 BST).
Top seed Serena Williams plays Galina Voskoboeva in the third match on Arthur Ashe Stadium, while American 15th seed Sloane Stephens and Urszula Radwanska follow Murray's match in the night session.
Murray, 26, is ready to face a barrage of attacking tennis when he finally steps onto court with Frenchman Llodra.
The third seed has won all three of his previous matches against Llodra, who enjoys coming to the net and will be hoping for a hot evening in New York.
"The conditions here obviously can change a lot from day to day," said Murray. "When it's warm here it's pretty quick, probably the quickest of the Slams.
"When it's cool in the evening, it slows down significantly, so I'll have to wait and see.
"It's a tough match. Llodra is a tricky player, serves well, one of the best doubles player in the world just now, very good hands, and he's very unpredictable.
"You need to be switched on all the time against him and play a solid match. You can't have too many ups and downs against him because he will capitalise on that."
Murray, who will have been in New York for nearly two weeks by the time he steps on court, insists defending his title will not heighten the tension.
"I think there is less pressure," he said. "I think before the first match there will be nerves there - I expect to be pretty nervous because it's a new experience and it's different - but I think once the tournament gets going, I don't think it changes too much.
"There was a lot of pressure on me for a lot of years to win a Grand Slam, and then the same sort of thing at Wimbledon. I wouldn't imagine it would be the same here."
Murray currently holds two of the four Grand Slam titles but is some way behind Novak Djokovic and Rafael Nadal in the rankings.
He is unlikely to reach the number one spot for the first time in the near future, but the Scot remains firmly focused on collecting major titles.
"Everyone is motivated by different things," he said. "My whole career for four, five, six years back, it was about winning Grand Slams. That was what gave me the motivation to train.
"When I did lose in a Grand Slam, that was what was most disappointing for me.
"I could win a Masters Series event and the first question I would get asked was, 'When are you going to win a Grand Slam?' It wasn't, 'When are you going to get to number one?'
"That became my motivation, to try to win Grand Slams, so that, I would imagine, would be the case for the rest of my career."