Jose Mourinho has confirmed in his pre-match press conference that Thibaut Courtois will miss Chelsea's game against Hull City on Saturday.
Speaking to the press Mourinho said the Belgian international has a small muscle problem and will not be risked against the Tigers with Petr Cech in reserve.
"Courtois had a little problem in training, a muscular problem, and he's not available for tomorrow," said Mourinho.
"Petr Cech had our confidence even when Courtois was playing. We know what we have, he has absolutely nothing to prove."
Courtois won his place as first-choice Chelsea keeper at the beginning of the season, beating out competition from previous incumbent Cech.
The 22-year-old has been an ever present in the Chelsea goal so far this season in the league, but Mourinho sees no point in taking any chances with his fitness as the Blues have a hectic fixture list over the next month.
Petr Cech had our confidence even when Courtois was playing - Jose Mourinho
Busy fixture list
They face Hull City at Stamford Bridge on Saturday, before matches against Stoke City, West Ham and Southampton before the end of the month.
Chelsea beat Sporting Lisbon 3-1 in mid-week, qualifying for the knockout round of the Champions League top of their group.