Chelsea could be without goalkeeper Petr Cech for the holiday period after they learned that he suffered bruising in Sunday's win at Blackburn.
Any long-term injury to Cech would be a huge blow to Chelsea
A Chelsea statement said: "Scans have shown bruising around Petr's hip and side. We will continue to monitor the situation over the coming days.
"We hope to have him back playing as soon as possible."
With Carlo Cudicini also out injured, Hilario could play against Aston Villa, Newcastle and Fulham.
The Portuguese keeper made his first appearance since 13 January as a 48th minute substitute for Cech at Ewood Park and kept a clean sheet as Chelsea won 1-0 through Joe Cole's first-half goal.
Cudicini is sidelined after suffering a rib injury in training and the statement continued: "Carlo also continues to make progress from his injury and again we hope to have him available as soon as possible."
Captain John Terry and Didier Drogba are already out because of injury and other players will be absent in January because of the African Cup of Nations.
"I wanted to take him (Cech) off, but he told me he wanted five minutes more to see if the injury would improve," Grant explained.
The result means Chelsea remain third at Christmas, six points behind leaders Arsenal and five behind second-placed Manchester United.
"It was difficult for Hilario to come into a game like this, but he did very well, and in the end he made a very good save," Grant added.