Chelsea centre-back Thiago Silva will spend at least a week on the sidelines after sustaining an injury reports The Times.
The Brazilian was withdrawn during the Blues’ 2-0 loss to Tottenham Hotspur on Sunday.
Chelsea play Leeds United on Saturday before welcoming Borussia Dortmund to Stamford Bridge on Tuesday.
Silva is having scans on his left knee and will be unavailable for both games.
It is a blow for the west London club amid their poor run of form.
The Blues have won just two of their last 15 games across all competitions.
Manager Graham Potter is under growing pressure despite the club owners backing him.
Chelsea are 10th in the Premier League after 24 games, with 14 points between them and the top four.
They lost 1-0 in the first leg of their Champions League round of 16 tie against Dortmund.
Potter’s side face a huge task to turn things around in the second leg.
Silva’s unavailability could prove catastrophic given his huge experience and quality.
The 38-year-old has played 27 games across the Champions League and Premier League this term.
He was recently rewarded with a one-year extension for his brilliant performances in the club’s colours.
Chelsea omitted French centre-back Benoit Badiashile from their Champions League squad.
However, they boast quality squad depth in defence and would not have an issue with selection.
Wesley Fofana replaced Silva on Sunday and could play alongside Kalidou Koulibaly again for the next two games.
Potter may have to win both to retain his job, and he has to do it without his best centre-back.
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