Skipper Terry, told by Ancelotti to be honest about the state of his body before the Blues made it four straight wins, did exactly that as he suffered from a first-half clash with Carlton Cole.
Terry, whose rib injury worsened as the game went on, asked to be replaced and will be scanned before Ancelotti confirms his squad for tomorrow's Champions League flight to Zilina in Slovakia.
Ancelotti said: "John said to me he had a problem and asked to be taken out. I brought Nicolas Anelka off because Drogba is suspended so he will play on Wednesday.
"We hope John and Frank will be fit but they have to be able to train properly before I can consider them."