Chelsea coach Carlo Ancelotti has admitted that long-term injuries to captain John Terry and Brazilian defender Alex may force him to strengthen his squad in the January transfer window.
Terry and Alex both missed the 3-0 home defeat by Sunderland last Sunday.
Terry has struggled all season with a nerve problem in his right leg and he travelled to Italy to see a specialist recommended by Ancelotti in midweek.
Terry is understood to be feeling slightly better but is still not pain-free enough to be considered for the trip to Birmingham today.
Alex meanwhile, has postponed surgery on his knee problem in order to play against Birmingham.
When asked if he would move into the transfer market if both players were sidelined for a long spell, Ancelotti replied: “It depends what happens with Alex and in the next few days with John Terry.
“Obviously, if both players are not able to play for a long time, I think we have to think about this. But just in that case.
“Tomorrow Alex will be available, which is good news. He trained well for the Brazilian team. We know he needs surgery, but we can procrastinate for this. There's no risk, but his knee needs to be clean.
“It will be good to have him back. We didn't play well last week, played a poor game. It was the first time in my period here, so we need to move on immediately and have a reaction.
“We want to forget Sunderland with a fantastic performance.”