Coronavirus is threatening to cause trouble at the Tour de France ahead of Saturday's start.
The disease played havoc with the world's top cycling race in 2020 and 2021 before abating, but a surge in cases among this year's teams means some old protocols are being brought back.
Superstar Tadej Pogacar caught Covid-19 during his preparation but symptoms were mild.
Belgian time trial world champion Remco Evenepoel has decided to wear a mask and in the team of Danish defending champion Jonas Vingegaard, PCR tests and hand disinfection are once again part of standard procedures in addition to masks.
"I don't want to scare people that I'm ill. I'm fine, but I'm being careful," said Evenepoel, adding: "We come into contact with a lot of people here. I don't want to finish the Tour like the Giro last year."
In 2023, Evenepoel dropped out on the first rest day at the Giro while leading after contracting an infection.
In Vingegaard's team Visma-Lease a bike, coronavirus has hit Vuelta champion Sepp Kuss hard and he is ruled out.
"Sepp is very valuable. We'll miss him a lot. Not just me, but the whole team," said Vingegaard.
Pogacar got off lightly, he said.
"I've recovered well. Covid is no longer as serious as it was back then. I already had the virus. The body gets used to it. It wasn't that bad and passed quickly," he added.
There are no official coronavirus protocols from organizers and any measures are being left up to teams.
Coronavirus was also a minor problem at the recent European Athletics Championships in Rome and Olympic organizers in Paris will be hoping it does not cause major issues in the Games from July 26-August 11.
