With Didier Drogba also about to depart for African Nations Cup duty, Chelsea's squad is suddenly at full stretch and coach Carlo Ancelotti said it was a chance for some of the fringe players to make their mark.
"Anelka has a small muscle problem but he is not ready to play these games," Ancelotti told Chelsea's website.
"We have some problems because we have to play without Anelka, Essien and Deco in these games."
Chelsea face Birmingham City away on Saturday and Fulham at home on Monday, hoping to consolidate their four-point lead at the top of the league.
Drogba will play at Birmingham where he will be partnered up front by former Manchester City youngster Dean Sturridge but that could be his final appearance before joining up with his Ivory Coast colleagues.
"Sturridge has a good opportunity to show his quality," Ancelotti said. "He played against West Ham very well in the second half and against Birmingham can play from the beginning.
"I have a lot of confidence in my strikers, not only Drogba, not only Salomon Kalou, not only Anelka, also Sturridge and (Fabio) Borini. Against Fulham maybe we have only Sturridge and Borini, but in January we have Anelka."
Ancelotti is aware that Chelsea are not firing on all cylinders, having won just once in their last six matches, and stressed the importance of the Christmas fixtures against two of the country's in-form teams.
"It's very important," he said. "We are in a very good position, we are four points top, it's not our best moment because we didn't play well the last games but for this we have to stay concentrated and focused to try to win.
"We play against very strong teams, Birmingham arrived from five consecutive victories and one draw. They are difficult to play, they are very strong and work hard for 90 minutes with a lot of pressure. It is a difficult game for us."
