Andy Murray must wait until 1600 BST on Wednesday to resume his US Open campaign after heavy rain meant the entire day nine schedule was cancelled.
Murray was due to face Donald Young in round four on Tuesday but the poor weather prevented play on any courts.
"The forecast indicates worsening conditions with no projected breaks in the rain through the day and into the night," read a US Open statement.
The men's final has taken place on the third Monday for the past three years.
Bad weather is once again affecting this year's schedule, and a packed order of play for Wednesday begins with Nadal facing Gilles Muller on Arthur Ashe Stadium while home favourite Andy Roddick takes on fifth seed David Ferrer on Louis Armstrong.
Murray and Young have been moved from Arthur Ashe Stadium to the third show court, the Grandstand, with all three matches taking place at 1600 BST.
The remaining men's fourth-round clash between John Isner and Gilles Simon follows Murray's match, while all four women's quarter-finals and the first two men's quarters are set to be played - weather permitting.
More rain, however, is expected at Flushing Meadows.
"We're playing it by ear, half-hour by half-hour, trying to get them on," said tournament referee Brian Earley before play was called off.
"We need the bottom half of the men's draw played as quickly as we can. The other half of the men's draw and the whole of the women's draw are into the quarter-finals already.
"I'm confident of finishing the men's tournament on Sunday and the women's on Saturday. There are some challenges down the road but we'll take it one day at a time."
Unless the men's final is pushed back, Murray will have to win four best of five-set matches in five days if he is to lift the title.Young is in the fourth round of a Grand Slam for the first time
He and Young, 22, will be going head-to-head for the second time, with the American wildcard looking to repeat his shock victory over Murray in Indian Wells in March.
"It's a big match for me," said the 24-year-old Scot. "He's talented, so he can hit winners from all parts of the court. That's why he's dangerous.
"He comes forward pretty well, he volleys good, he's got nice feel around the net and he's got quite easy power, which can be sometimes difficult.
"Guys look like they're not winding up to hit a big shot, and he can create quite a lot of power. He's got a big first serve when he goes for it, but he can be a little bit inconsistent as well.
"He's flashy. He can get on a roll. He's tough."
World number four Murray, who needed five sets to get past Robin Haase in round two, booked his place in the fourth round with a comfortable straight-sets win over Feliciano Lopez on Sunday.
And he is now keen to make amends for the defeat by Young in March, which was followed by another shock loss against Alex Bogomolov Jr in Miami as the Briton struggled to deal with defeat in January's Australian Open final.
