Chelsea could be without Petr Cech for the festive programme after scans revealed the goalkeeper suffered bruising around his hip and side at Blackburn on Sunday.
Cech was injured in the second half of the 1-0 win at Ewood Park and, with regular number two Carlo Cudicini also missing (rib), the injury-plagued Blues had to turn to third-choice keeper Hilario.
The veteran Portuguese keeper made his first appearance in almost 12 months when he came on in the 64th minute.
Chelsea coach Avram Grant is already without key duo John Terry (foot) and Didier Drogba (knee) and his number one keeper could also now be set for a spell on the sidelines at a vital time of the season.
The Blues host Aston Villa on Boxing Day and Newcastle United on December 29, before a New Year's Day trip to Fulham.
"Scans have shown bruising around Petr's hip and side," read a club statement.
"We will continue to monitor the situation over the coming days and hope to have him back playing as soon as possible.
"Carlo Cudicini also continues to make progress from his rib injury and, again, we hope to have him available as soon as possible."