Terry didn't train with the Blues on Monday, so he could be fitted for a molded mask that will protect the small piece of broken bone.
Chelsea manager Avram Grant says England and Chelsea can be proud that Terry is their captain.
"He's someone who sets a good example, not one who says many things and doesn't back it up," said Grant. "He's injured but wanted to continue in the last game. He wants to play for the team and give everything he can. He's brave, he's a nice guy and his commitment is incredible. It's not an easy time and we need John Terry. He's here for us."
Wednesday's game is Grant's first Champions League challenge since taking over for Jose Mourinho after Chelsea was held to a 1-1 home tie by Norway's Rosenborg in their opening Group B game two weeks ago.
It couldn't come against a hotter opponent. Valencia goes into the game with seven successive wins in all competitions. The Spanish club will be out for revenge after being knocked out of the Champions League by Chelsea in last season's quarterfinals.
Chelsea will be without midfield stars Frank Lampard and Michael Ballack. Valencia goalkeeper Santiago Canizares is unlikely to play, while Vicente, Manuel Fernandes and Carlos Marchena are also doubtful.
Chelsea -- Cech; Belletti, Terry, Ben Haim, A.Cole; J.Cole, Mikel, Essien, Malouda; Shevchenko, Drogba.
Valencia -- Hilderbrand; Miguel, Albiol, Helguera, Moretti; Joaquin, Albelda, Marchena, David Silva; David Villa, Morientes.
Referee: Roberto Rosetti (Italy).