Roger Federer and Rafa Nadal are seemingly not the only ones sick of the sight of Novak Djokovic and his domination of men's tennis.
At the US Open on Tuesday, food poisoning victim Conor Niland of Ireland threw up then gave up during his first-round match with the world No. 1. He lasted only 44 minutes. Trailing 0-6, 1-5, he retired.
Perhaps the only thing in professional tennis looking more under the weather right now is the state of the women's game. After just two days at Flushing Meadows, not one reigning grand slam singles champion is left in the draw.
On Monday, Wimbledon champion Petra Kvitova, made an inglorious early exit and was joined a day later by China's Li Na, the French Open winner. Li was shown the door by Simona Halep of Romania 2-6, 5-7.
It is little wonder that Serena Williams, less than a month away from turning 30 and in the early stages of a comeback after surviving a life-threatening lung disorder, has been installed as the favourite to win.
The American sent an ominous warning to her rivals when she began her campaign with a 6-1, 6-1 win over Serbia's Bojana Jovanovski.
Nadal began his title defense with a straight sets win over Andrey Golubev of Kazakhstan. The Spaniard won 6-3, 7-6, 7-5 but it was a performance that raised as many questions as answers.
"It's a positive start," Nadal said. "It was unbelievable that I won straight sets, but it is still a victory in straight sets."
Caroline Wozniacki, the women's world No. 1, provided a glimpse of the ruthless streak her critics have accused her of lacking, demolishing unseeded Spaniard Nuria Llagostera Vives 6-3, 6-1. The Dane smashed 22 winners in a lopsided victory that took just 80 minutes.