Didier Drogba has warned his Chelsea team-mates they can not use the absence of key players as an excuse for the team's recent poor form.
Chelsea lost top spot in the Premier League over the weekend and have won just once in their last five top-flight matches.
The reigning champions have been missing Frank Lampard, John Terry and Michael Essien in recent fixtures, but Drogba is adamant that is no excuse for the Blues' form.
Drogba feels it is the most disappointing spell of form since he moved to Stamford Bridge in 2004 and believes the upcoming month, when Chelsea face Manchester United and Arsenal, could be decisive in this season's title race.
"It is maybe the worst run of form I've known since I came to the club," said Drogba. "It is not good.
"It is very frustrating - very frustrating. I know that during the season you can have moments like this and try your best to change it."
He added: "We are playing those teams around us in the next few weeks so this is a challenge that we have to do everything to win.
"We are glad to get November out of the way - now let's see what December brings.
"We can't use the players who are out as an excuse, even if they are key players.
"When you sign for Chelsea, you know you have to give your best. You know you've signed for the best team so you have to improve your game, especially when players like Terry, Lampard and Essien are not there.
"This is the moment when you have to show you are able to take responsibility because you know it won't be easy.
"It's only going to happen from us. We can't expect people to come and say 'OK, we'll change it for you'.
"We have to change it as players, with the manager, all of us together. We have to stay together as a team.
"You might say this is the basic formula from players but we have to stay together and do everything to change this."
