Chelsea head coach Thomas Tuchel has revealed that Mateo Kovacic has tested positive for coronavirus.
Having been absent since October 26 through injury, the midfielder made his return to the training pitch on Monday, putting him in contention for Saturday's Premier League game with Leeds United.
However, the 27-year-old has now tested positive for coronavirus, and Tuchel could not hide his frustration as he spoke to the media on Tuesday.
The German told reporters: "We have bad news because Mateo was in training yesterday with a big smile and it was pure pleasure to have him back, but now he has tested positive for coronavirus.
"He is isolating and out for another several days. It's a huge setback for him personally and for all of us."
Given that the Croatia international will also need to come through training sessions with the team upon his return, he may not come back into contention until the trip to Wolverhampton Wanderers on December 19.
