Chelsea manager Thomas Tuchel has tested positive for Covid-19 just days before the Blues' Club World Cup campaign gets underway, the club have confirmed.
"The Chelsea head coach will now follow necessary self-isolation protocols and hopes to join up with the team in Abu Dhabi later next week," a statement from the European champions reads.
"The team fly out for the Club World Cup following this afternoon's FA Cup clash with Plymouth Argyle."
Chelsea are Europe's representatives in the Club World Cup after beating Manchester City in the 2020-21 Champions League final.
They will face either Al-Jazira of the UAE or Al-Hilal of Saudi Arabia in the semi-finals of the competition, before taking on one of Palmeiras, Monterrey or Al Ahly in the final.
Chelsea have confirmed Arno Michels will be in the dugout for the cup game.
The first-team coach joined Chelsea at the same time as Tuchel, having also worked with his fellow German at Mainz, Borussia Dortmund and Paris Saint-Germain.
A number of Chelsea players tested positive for Covid earlier in the season, impacting the Blues' efforts to stay in touch at the top of the Premier League.
Several first-teamers returned positive tests in mid-December, with Tuchel's side requesting a postponement of their Premier League game against Wolverhampton Wanderers before Christmas but seeing the request turned down.
"We are deeply disappointed that our application was rejected as we felt we had a strong case for the postponement of today's match on the grounds of players' health and safety," a club spokesperson said at the time.
Chelsea's trip to the Club World Cup means the cup game against Plymouth is their last in England until February 19.
The London side also took part in the tournament back in 2012, after winning the Champions League during Roberto di Matteo's time in charge, and will hope to go better after losing the final on that occasion.
Chelsea beat Monterrey in their 2012 semi-final, but were beaten by South American champions Corinthians in the final in Japan thanks to a Paolo Guerrero goal.
With Tuchel self-isolating, he will not be in the dugout for Chelsea's cup game against Plymouth.
The Blues beat non-league Chesterfield 5-1 in the third round of the competition, while their fourth round opponents - currently in League One - pulled off an extra-time victory at Birmingham City.
"We feel very prepared, and it was also necessary because we respect the opponent, the competition and the situation that for them it's a unique game and opportunity to show, in a situation where they have absolutely nothing to lose," Tuchel said in his press conference ahead of the game.
Chelsea made it all the way to the final under Tuchel last season, eventually losing at the final hurdle against Leicester City.
They are also in the final of the Carabao Cup after beating Tottenham Hotspur home and away in the semis, with Liverpool awaiting in the Wembley showpiece at the end of February.