Reo-Coker caught the Ghanaian international in a fair but late challenge after only 9 minutes on was given a warning by referee Howard Webb.
Essien, the villain of so many controversial tackles himself of late, was replaced by Eidur Gudjohnsen and left Upton Park on crutches to go for X-rays and scans on his ankle.
Chelsea’s manager Jose Mourinho said after the game, “Essien cannot walk and his foot and ankle are both very swollen.”
Hammers boss Alan Pardew will be happy today though after an unnamed FA spokesman confirmed, “There will not be any disciplinary action because the referee dealt with the matter at the time by awarding a free-kick to Chelsea.”