London - Chelsea manager Jose Mourinho is unsure if the Premier League champions are over the worst following their poor start to the season, but he said on Friday that a win and two clean sheets in the last week had lifted everyone at the club.
Chelsea made their worst start to a domestic season for 37 years, recording only two wins in their opening eight Premier League matches.
Yet a 2-0 victory over Aston Villa last Saturday and a 0-0 draw with Dynamo Kiev in the Champions League on Tuesday showed signs of improvement, according to the Portuguese boss.
Asked if their surprising slump was now over, he replied: "I don't know. The players were always together and were man enough to assume their responsibilities and for some of them to say publicly they were individually responsible for the poor start.
"The statistics are very simple. We conceded six goals as a consequence of isolated individual mistakes, but we were always together.
"At this moment we have had two important results - three points in the Premier League after two matches without a victory and against a direct rival in the Champions League we got a point away.
"We were always solid, compact and together but obviously the mood improves with the results. I never went in the crisis direction, I just go match after match."
Chelsea travel from west to east London for Saturday's derby against a West Ham United side riding high in fourth place and Mourinho said he knew Chelsea were in for a tough afternoon at Upton Park.
"You only have to look at the table," he said, before adding that he had been impressed by West Ham's coach Slaven Bilic, who took over from Sam Allardyce after last season ended.
"As a coach I like him a lot. Since the Croatian national team period, to Besiktas and now to West Ham, I have a very good image and idea about him.
"As a person I don't know him very well but I have the feeling we could be friends."
Chelsea will be without the injured Pedro, Loic Remy, Branislav Ivanovic and Thibaut Courtois for the game at a ground where they have excelled in recent years.
The last nine Premier League matches between the teams at Upton Park have resulted in seven Chelsea wins, a draw and a solitary win for West Ham nearly three years ago.