Novak Djokovic won't mind if it rains for the next two weeks in New York.

The U.S. Open's Arthur Ashe Stadium is now covered by a retractable roof. And based on his experiences at the Australian Open and Wimbledon, which already have one, the 12-time major champ expects more humid conditions once the panels slide shut — which make for a slower court.

"It allows returners like myself to get into the rally rather than seeing missiles pass by from the serves," Djokovic said Friday.

He added with a chuckle: "I wouldn't complain, honestly, to play an indoor U.S. Open throughout the whole two weeks."

The world's top-ranked player insisted he won't wake up every morning praying for rain, and his stellar return game certainly doesn't need much help. Roger Federer, sidelined by a knee injury, also predicted this week that the roof will aid Djokovic. The Serb begins the defense of his U.S. Open title Monday night on Ashe, where he'll likely play all his matches.

The approximately $150 million project to construct a roof over Ashe features an air management system and sliding shutters that seal the stadium, designed to try to minimize the humidity Djokovic so enjoys.

U.S. Tennis Association officials say tests have shown little difference in the conditions open or closed, but the proof will come once matches are first held under the roof.

When that will be is for Mother Nature to determine. Wimbledon champ Andy Murray — who has played in two Monday U.S. Open finals because of weather delays — couldn't help but quip: "I'll bet it doesn't rain this year."

Indeed, the extended forecast as of Sunday showed little chance of rain for the tournament's first week, though of course that can quickly change.

The U.S. Open has two meteorologists on site at all times who use proprietary software to track the likelihood of storms. They're located next door to the scheduling room for quick communication.

On some occasions when inclement weather is possible, the shutters around the stadium's upper bowl will start to close and the air management system will be activated to be ready in case the roof needs to be shut. The tournament referee makes the final call.

It takes about seven minutes for the roof to close, and if the court is dry, tournament director David Brewer said, the overall delay won't be much longer than that. The players won't leave the court during the process.

If it starts raining before the roof is closed, the interruption will be longer to dry the court, though Brewer hopes to avoid that scenario as much as possible.

"Frankly because we have so many people there and because so many people have asked for a roof for so long, I think we're going to be pre-emptive in our moves to stay ahead of the weather a little bit," he said.

For the most part, if the roof closes during a match, it will remain shut until the end. It could then be reopened for a subsequent match.

The roof will never be partially closed to provide shade, and it will be shut only for rain, not for extreme heat. The structure supporting the roof does already provide more shade than before.

During the U.S. Open's first week, rain would still wreak havoc with the schedule because no other courts are covered. Additional matches could be moved onto Ashe if need be. Brewer would prefer not to shift an in-progress match from another stadium onto Ashe, but situations may arise when that's unavoidable.

Even if it never rains, the roof is guaranteed to be closed at least once in the next two weeks. It will be shut at the start of Phil Collins' opening ceremony concert Monday night, then slide open during the performance.