Why Are So Many Players Getting Sick at the U.S. Open?

Early in the second set of her second-round match on Thursday night, a ball bounced just past Ons Jabeur’s reach, and she lost the point, throwing her arms up in exasperation.

On any normal day, Jabeur, the No. 5 seed, would probably have reached the ball in time to return it down the line, but she has been playing while sick.

Jabeur, who reached the U.S. Open final last year, is among several players who have had to contend with an illness of some sort at this year’s tournament.

Dominic Thiem of Austria retired in the second set of his second-round match, doubled over at the net with what appeared to be a stomach-related issue. Emil Ruusuvuori withdrew from the tournament before his first-round match, citing an unspecified illness. Tennys Sandgren, who failed to advance out of the qualifiers, wrote on X, formerly known as Twitter, that he became ill after returning home from the tournament.

“I got the us open bug,” he said in a separate post, adding, “in a way still feels like I’m in the tournament but at home.”

It’s not just players. The ESPN commentator John McEnroe said on Tuesday that he had tested positive for the coronavirus after feeling unwell.

It is unclear whether all of the players have the same illness, or whether their cases are connected, but something has been going around the U.S. Open.

Hubert Hurkacz seemed to struggle during his second-round match on Thursday, when he was upset by Jack Draper of Britain. During the match, medical staff came out to treat Hurkacz for what did not appear to be a physical injury. Around the tennis grounds, sniffles and coughs can be heard, and some players have been toting tissues in their bags.

The string of illnesses comes as a late-summer wave of coronavirus infections has been reported across the United States, with indications of a rise in cases in the Northeast and in the West.

Illnesses are possible at any tournament, where players are often in close quarters and share facilities. But with players no longer required to test for Covid-19, it is difficult to determine the cause of the illnesses among them.

Health protocols at the U.S. Open have become less stringent since 2020, when spectators were not allowed to attend the tournament and when players took to the empty courts in face masks.

When fans were allowed to return in 2021, they were required to show proof of vaccination against the coronavirus. That requirement has since been dropped, and those attending the U.S. Open this year do not need to show proof of vaccination, provide a negative coronavirus test or wear masks.

After willing her way — just barely — to a first-round win, Jabeur said she had the flu. In her second-round match, she appeared to struggle again, coughing on court several times, including during her interview after beating the unseeded Czech player Linda Noskova in three sets.

Jabeur said later in a news conference on Thursday that she had been sick for about a week.

“I’m taking a lot of medicine,” she said, adding that she “basically took every medication” the U.S. Open doctors have.

Jabeur said her stomach had been “fine,” but she noted that she knew other players had been struggling with stomach issues. She seemed to waver on whether she had the flu or something else.

“I think I got a flu or something,” she said on Thursday night.

It was unclear whether Jabeur, who plays her third-round match on Saturday against the No. 31 seed Marie Bouzkova of the Czech Republic, had taken a coronavirus test to rule out the possibility of an infection.

“I’m a zombie because I have a flu,” she said.