LIONEL Messi is isolating at home in Argentina after being among four Paris Saint-Germain (PSG) players announced Sunday as testing positive for the novel coronavirus ahead of the team’s return to playing after a brief winter break.

PSG Coach Mauricio Pochettino is uncertain when the seven-time Ballon d’Or winner will be able to return to France, or whether he can recover in time to play away to Lyon in the league next Sunday.

Leading clubs across Europe, including Barcelona and Real Madrid, have been depleted by novel coronavirus infections — reflecting a wider surge in case numbers on the continent spurred by the Omicron variant.

England has been the most affected as the Premier League has played on through the Christmas holidays amid a wave of postponements.

Liverpool announced three further suspected novel coronavirus cases ahead of kick-off at Chelsea on Sunday, with goalkeeper Alisson, forward Roberto Firmino and defender Joel Matip isolating. Manager Jürgen Klopp had already entered isolation and so missed the trip to London.

French clubs are back playing for the first time in 1 1/2 weeks, a break which allowed players to go home or take a holiday.

Mauricio Pochettino’s options for Monday’s French Cup match at third-tier Vannes have also been depleted by left back Juan Bernat, backup goalkeeper Sergio Rico and midfielder Nathan Bitumazala contracting COVID-19.

It’s unclear whether the quartet, including Messi, will be fit to play again, although PSG have a 13-point lead at the top of the standings.

“With regards to Leo, he’s in contact with our medical service,” Pochettino said. “I don’t know if he’ll be able to play in Lyon. He tested positive in Argentina [and] until he’s negative, he won’t be able to travel to France. We’ll see when he gets back.”

PSG resumed training earlier this week, raising the prospect of further infections in the squad.

“It’s the risk everyone runs in football on a world scale,” Pochettino said. “Contact is unavoidable in football; it’s obvious that there are more risks,” he said. “We’ve taken all the steps necessary to avoid a player transmitting the virus to another. I do what the medical service personnel tell us to.”

Monaco said Saturday that seven players had COVID-19 but none showed any worrying signs and are isolating.