Italy's Matteo Berrettini, one of the favourites for the men's singles, has withdrawn from Wimbledon after testing positive for Covid-19.
The 26-year-old, seeded eighth, was beaten by Novak Djokovic in last year's final and recently won the Queen's title.
"I am heartbroken," said Berrettini, who said he has had flu symptoms and been isolating for the past few days.
He has been replaced in the draw by lucky loser Elias Ymer of Sweden.
"I have no words to describe the extreme disappointment I feel," added Berrettini.
"The dream is over for this year, but I will be back stronger.