"It is my ankle. I'm going to get it scanned. I don't know if I'll be fit for Wednesday at the moment," Terry told the Daily Mirror.
Frank Lampard admitted it would be a huge blow to lose Terry and that he felt for the defender after missing out on last season's Champions League success in Munich.
"It's a huge blow," noted Lampard. "I am gutted for him because I know how difficult that was for him, missing the game last year.
"But whatever we do as a club, John is part of it. We win things together."