Diego Costa and Victor Moses were victims of the same sickness bug that caused Marcos Alonso to miss Sunday's defeat to Manchester United.
Antonio Conte's preparations for the match at Old Trafford were disrupted as left-back Alonso withdrew from the starting XI during the warm-up and it is understood that Moses and Costa decided to play despite not feeling 100 per cent.
The three players are believed to have felt sick after a team meal on Thursday and it has emerged they all missed training on Friday.
Sky Sports News HQ also understands Courtois sustained an ankle problem while playing basketball in a commercial shoot.
After the match Chelsea manager Antonio Conte accepted responsibility for his side's uninspiring performance that meant the leaders' advantage over Tottenham remained at four points.
Alonso, Moses, Costa and Courtois are all expected to be fit to face Tottenham in the highly anticipated FA Cup semi-final at Wembley on Saturday.