Petr Cech will today discover if he faces another spell on the sidelines that could see him miss the remainder of the festive programme.
The Chelsea goalkeeper will undergo scans on a side strain sustained early in the second half of yesterday's 1-0 victory over Blackburn at Ewood Park.
An innocuous collision with striker Roque Santa Cruz led to Cech requiring lengthy treatment, and although he played on for another 11 minutes, it was obvious he was in too much pain to continue.
It led to Hilario making his first appearance since January 13 as Carlo Cudicini is also out with a training-ground rib injury.
With three games coming up in the next seven days, now is not the time for coach Avram Grant to be without two of his goalkeeping stars.
'We will know the situation with Petr when he goes for his scans,' said Grant, whose side are hanging onto the coat-tails of leaders Arsenal and second-placed Manchester United.
With captain John Terry and striker Didier Drogba also out, the Blues potentially face the next few matches without the spine of their team.
'I cannot say it will be easy if we lose Cech,' added Grant.
'To play for so long with so many injured for a long time, I don't like it, but I cannot do anything about it.
'It's fact, and we need to get through it as soon as possible like we have done in the last three months.'
Grant rightly conceded it was not the prettiest of performances from his team, but they again managed to get the job done.
A searing 22nd-minute drive from Joe Cole was all that separated the teams, and courtesy of saves from Cech, Hilario and with the aid of the woodwork, it is now just one defeat in 19 matches for Chelsea.
If they are to gain points from the next three games, with Aston Villa, Newcastle and Fulham looming, Cole knows exactly what is required.
'What a result in the end because I don't think too many teams will come here and get many points,' said the midfielder.
'We didn't play well or pass the ball as well as we would like, but we showed great spirit and great desire, the qualities that have made us very successful over the years.
'We know the task ahead. We don't look at the other results, we just have to keep winning.'
It was Chelsea's seventh win in nine league visits to Blackburn, who have now lost their last four games and taken just five points from the last 24 on offer.
Boss Mark Hughes, though, knows his side are doing little wrong and he said: 'We showed real quality, especially in the first half.
'Our play was really dynamic and we created good chances, hitting the bar a couple of times.
'Against lesser opposition, the chances we created would have been taken and we would have won the game.
'Unfortunately we were caught with a sucker punch. But we were up against one of the top teams in the country, and in fairness we acquitted ourselves very well.'