UEFA in Thursday cautioned teams like Chelsea and Real Madrid must “in principle” comply with France’s new vaccine passport when the Champions League knockout rounds start one month from now.

Government sources on Monday told AFP that all competitors who wish to enter sporting stadia and compete in France should be vaccinated against Covid-19.

Furthermore, it suggests that European titleholders Chelsea should leave any non-vaccinated players behind when they face Lille on March 16 in the last 16, and Real Madrid, who are at Paris Saint-Germain on February 15.

UEFA is liaising with the relevant stakeholders across Europe ahead of the resumption of UEFA’s club competitions in February,” European football’s governing body said in a statement.

“The specific conditions under which matches are played in each country are subject to the decisions of the competent authorities in that country.

“Each team will in principle be required to comply with the applicable rules in the country where the match takes place.”

The statement went on to note that “the specific competition Annexes – still under elaboration – which contain special rules due to COVID-19 applicable to the knock-out phase, may provide further guidance in this regard.”