Roger Federer is aiming for a 20th Grand Slam singles title at the US Open. Photo: Julio Cortez, AP

NEW YORK – Blue skies and bright sunshine greeted fans at the US Open on Monday, where world number one Rafa Nadal and third seed Roger Federer were scheduled to play under an open roof at Arthur Ashe Stadium.

After wet weather on Sunday postponed matches on outside courts, fans arriving on Monday will first be treated to an enticing centre court match between big-serving world number one Karolina Pliskova and unseeded American Jennifer Brady.

Nadal will then face Ukrainian Alexandr Dolgopolov, who was last seen lashing out at the media when asked about the Tennis Integrity Unit looking into match-fixing allegations following his loss in a tournament last month.

Fan favourite Federer will kick off the evening session on Ashe, and will try to sustain the momentum he built up in his straight-sets win over Spaniard Feliciano Lopez in the third round when he faces unseeded German Philipp Kohlschreiber.

Monday is the Labor Day holiday in the US and to celebrate, the US Open is hosting its first Military Appreciation Day at Flushing Meadows, which will include discounted tickets for the military and appearances by high-ranking officers, who will conduct the ceremonial coin tosses before matches.