Petr Cech has admitted that he let Chelsea down in the side's 1-1 draw against Wigan on Saturday.
The Czech international fumbled a late Hugo Rodallega shot and Jordi Gomez scored to earn Wigan a share of the points at the DW Stadium.
The draw was a significant setback for Chelsea as they looked to build on their victory over league leaders Manchester City.
"One of my teammates ran across my view-point, I lost the ball from my view and it bounced off me," the goalkeeper told the club's official site.
"It's bad luck but, despite all that, I should have coped with it. I shouldn't let in such goals.
"This has downgraded the win over City in a way but there is nothing we can do now.
"There are lots of matches to be played and already on Thursday we have the big derby at Tottenham, who are with us inside the top four and we need to beat them."
Chelsea sit in 4th place and are currently nine points adrift of Manchester City.