Chelsea forward Kai Havertz has gone into self-isolation after testing positive for the coronavirus.
Havertz's Covid-19 test was revealed after the German was missing from Chelsea's squad for their Champions League clash with Rennes at Stamford Bridge on Wednesday.
"Frank Lampard has confirmed Kai Havertz has tested positive for Covid-19," a statement on Chelsea's website said.
"As a consequence the player is now undergoing a period of self-isolation and is not involved in tonight's Champions League game versus Rennes."
Havertz has endured a difficult start to his time at Chelsea since joining from Bayer Leverkusen in the close-season.
The 21-year-old has scored just one goal in the Premier League, struggling to reach his peak form after being used in a variety of positions by Blues boss Frank Lampard.