If there was bleeding around the brain, this could lead to further neurological problems, forcing Cech out for many months.
Whatever happens, he will need several months of brain scans before getting a clean bill of health.
Irrespective of the pressure from Chelsea, the FA had already announced its intention to open a video investigation of all the matters arising from the match.
"We will study the referee's report and look at footage from the match before deciding whether to take any action," said the FA last night.
Despite a potential goalkeeper crisis for Wednesday's Champions League match at home to Barcelona, it is expected that Chelsea will seek the advice of a neurosurgery specialist before determining Cudicini's fitness to play.
The injury is likely to leave him on the sidelines for several months.