This could be a real crisis. Chelsea and Real Madrid's unvaccinated players could be forced out of the upcoming UEFA Champions League last 16 away leg ties in France.
So what's really going on? The two clubs are scheduled to travel to France to face Paris Saint-Germain and Lille respectively.
Los Blancos are expected at PSG on 15 February, while the Blues will visit Lille on 16 March. According to ESPN's report, unvaccinated players from the two team will not be permitted to enter France.
"French lawmakers have approved a change that is set to come into effect on Monday, modifying the country's coronavirus health pass into a vaccine pass," the report said.
"This means only vaccinated people or anyone who has recently recovered from COVID-19 will be able to enter large arenas.
French sports minister Roxana Maracineanu insisted last week that it would apply to "all spectators, athletes, French or foreign professionals," raising serious doubts over the involvement of any unvaccinated players in Real's or Chelsea's squads.
UEFA told ESPN in a statement on Thursday that clubs would have to adhere to the rules in each country, but they are still in discussions over whether exemptions will be possible.
'"UEFA is liaising with the relevant stakeholders across Europe ahead of the resumption of UEFA's club competitions in February,"'the statement read.
Meanwhile, Chelsea are focused on their Premier League London derby as Tottenham Hotspur visit Stamford Bridge this weekend.