Head coach Thomas Tuchel has highlighted that Chelsea are taking extra risks by promoting several players from the club's academy squad for the EFL Cup quarter-final with Brentford.
On Monday, numerous youngsters linked up with the first-team group with at least nine players due to be missing for Wednesday's fixture.
However, Lewis Baker, a potential starter in midfield, has since tested positive, and Tuchel feels that it shows the dangers of bringing in people from outside of their own senior bubble.
Speaking to reporters at a press conference, Tuchel said: "We make them come for two training sessions because it is necessary. When we made them come, we detected that Lewis Baker for Covid, so we are also taking a risk to bring players in from the academy who have it.
"It's no secret (that academy players trained yesterday). We think about playing with them."
Tuchel has revealed that Jorginho is the only player who will return to the squad after seemingly recording a false-positive coronavirus result.