Chelsea's worst run of form in more than a decade is giving Carlo Ancelotti sleepless nights as the Blues begin a potentially season-defining sequence of fixtures at Tottenham on Sunday.
The Premier League champions' protracted slump could easily develop into something more serious if results go against Chelsea over the next fortnight, when they face Spurs, Manchester United and Arsenal in quick succession. Ancelotti's men have taken just five points from a possible 18 in their last six matches, and have not registered a victory in the Premier League since beating Fulham 1-0 a month ago.
The sense that Chelsea's season is unravelling escalated in mid-week when they suffered their first defeat of their UEFA Champions League campaign in a 1-0 loss against French champions Marseille. Ancelotti, whose future at Stamford Bridge has been the subject of intense speculation after assistant Ray Wilkins was fired against his wishes, admits his side's confidence had collapsed.
"The bad moment continues and we have lost confidence in our play now but we have to come back and keep going," Ancelotti said. "Against Marseille was a good opportunity to move on from this period but we lost this opportunity - but now we have another good opportunity, against Tottenham.
"I am worried just because we are not doing our best, but I would like the team just to move on from this moment. I am strong and I am focused on my job, and I am sure my players are the same."
While defeat at White Hart Lane will inevitably be viewed as yet more evidence of Chelsea's decline, a victory could have a transformative effect. With leaders Arsenal not playing second-placed Manchester United until Monday, an away win for Chelsea on Sunday will be enough to see them go top, albeit if only for 24 hours.
Tottenham, riding high after securing first place in their Champions League group, will be desperate for a victory to maintain their push for a fourth-place finish or better. Spurs are currently three points behind fourth-placed Manchester City, who travel to relegation-threatened bottom club West Ham on Saturday.
City boss Roberto Mancini has warned his side against complacency, insisting the Hammers' position at the foot of the table is not a true indicator of their quality. "West Ham will be a difficult game because they are having a bad time at the moment, but I think they have a good squad," said the Italian.
"They don't deserve to be bottom of the table and it is going to be a tricky game. But we need to play the same, away or at home, and our record away is good this season."
Outside of the title race, all eyes will be on St James' Park, where Newcastle manager Alan Pardew faces a difficult first match in charge after yet another tumultuous week in the club's rollercoaster recent history. If the dismissal of manager Chris Hughton was greeted with widespread incredulity throughout football, the appointment of Pardew as his successor on Thursday was met with even greater surprise.
Pardew, who has not worked in the Premier League since overseeing Charlton Athletic's relegation in 2007, admits he is struggling to win the hearts and minds of the Toon Army ahead of Saturday's meeting with Liverpool. "I know I'm not going to win the PR battle. That's just a battle I'm not going to win," Pardew said. "The battles I need to win are out on the pitch."