Things have gone from bad to worse for Barbora Krejcikova at the French Open.
The World No.2 in singles was forced to withdraw from the doubles at Roland Garros on Wednesday after testing positive for Covid-19.
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After a shock first-round loss in the singles on Monday, she is now unable to defend the doubles title she won last year with Katerina Siniakova.
“Last night I started to feel bad and this morning I woke up with fever," the Czech star wrote on social media.
"I decided to get tested for Covid and it came back positive.
“I am extremely sad that I won’t be able to defend my title in doubles here, but on the positive side, I am glad I am injury free and can’t wait to get healthy and back to training.”
The 26-year-old is the second player to test positive for Covid since the year’s second grand slam tournament began on Sunday.
Fellow Czech player Marie Bouzkova also withdrew from the clay-court event before her second-round singles match.
Bouzkova was supposed to face 31st seed Elise Mertens, who automatically advanced to the third round.
Bouzkova wrote on Twitter that she hopes she “will start to feel better soon and get back on court.”
The 23-year-old has never made it past the second round of a grand slam tournament in 13 appearances, including 10 losses in the first round.
Barbora Krejcikova's devastating new blow
Crejcikova made tennis history in 2021 when she won both the singles and doubles titles at Roland Garros.
But the devastating Covid blow comes two days after the defending champion made a shock-first round exit from the singles.
Krejcikova became just the third defending champion to be knocked out in the opening round at Roland Garros, losing to 97th-ranked Frenchwoman Diane Parry.
It was her first match in three months due to an elbow injury.
Speaking in her post-match press conference, Krejcikova broke down in tears as she admitted she "hit a wall".
"I just collapsed physically," she said.
"It was tough because I didn't play the matches. Matches are different to practices. I tried to prepare the best way I could.
“It was difficult. I mean, I expected it’s going to be difficult, and it was.
“I think overall, tennis-wise, it wasn’t that bad. I think physically, it was a little worse.”
The only other women to lose in the first round after winning the French Open title the year before are Anastasia Myskina in 2005 and Jelena Ostapenko in 2018.
Since the Open era began in 1968, Krejcikova is just the seventh reigning women's champion to be knocked out in the first round at any grand slam.
The World No.2 lost 6-1 2-6 3-6 on Monday to Diane Parry, a 19-year-old from France who is ranked 97th.
A year ago in Paris, Krejcikova was unseeded in singles but wound up with the championship, defeating Anastasia Pavlyuchenkova in the final.
She then teamed with Siniakova to win the doubles trophy, becoming the first woman since Mary Pierce in 2000 to win both the singles and doubles titles at the French Open in the same year.
Krejcikova out of doubles with covid. https://t.co/JnIzgZKFLs
— José Morgado (@josemorgado) May 25, 2022
The week gets worse for Krejcikova, who tests positive for COVID and can't compete in doubles. https://t.co/aIvFWG9yUO
— David Kane (@DKTNNS) May 25, 2022
Didn’t even make it to a week, never mind the fortnight! Horrible, terrible, no-good 3 days for poor Barbora!
— Kvittycat (@kvittycat53) May 25, 2022
Krejcikova gone down with covid. Following on from Bouzkova worrying times in Roland-Garros.
— Gary Kelly (@maxcouch) May 25, 2022
— chris🐊 (@sinnerap0va) May 25, 2022
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