Chelsea coach Carlo Ancelotti admits his side are in the midst of their toughest period since he took charge in the summer.
The Italian has watched his side stutter with defeat by Inter Milan in the Champions League followed by a 1-1 draw with Blackburn at Ewood Park.
But Chelsea have the chance to cut Manchester United's lead at the top of the Barclays Premier League to just a point by beating Portsmouth at Fratton Park tonight.
Ancelotti accepts nothing less than a win will suffice against crisis club Pompey as they look to return to winning ways.
"It's the most difficult moment of the season, this is true," said Ancelotti.
"It's more difficult now and we shouldn't be afraid to admit that. We're working hard to try and close this moment with a victory.
"Every team has had a difficult moment in the season. Now is a very important moment and we have to end it immediately.
"The start of this moment was the defeat to Manchester City and during this period we had a lot of injuries.
"But we have to look forward. I'm sure that, with our first victory, we'll come back to playing well."
Ancelotti remains convinced he will see out the remainder of his three-year contract even if he fails to bring any silverware to Stamford Bridge this season.
Chelsea have a history of replacing managers who don't bring success to the club but Ancelotti insists all that is in the past.
"I am here to change the history of this club," he added. "I am an optimistic man. I have a very good relationship with the club and with Roman (Abramovich). My position is not in discussion.
"I think the owner now is thinking what I think - to win the Premier League and to win the FA Cup."
Ancelotti has set his side a target of 86 points in order to win the title but there is one game, against Manchester United at Old Trafford in early April, he knows the Blues cannot afford to lose.
"We don't have to lose at Manchester United," said Ancelotti. "We can't afford to lose there. That is the only thing.
"We have nine or 10 games until the end of the season - eight in the Premier League and maybe two in the FA Cup - and that's not a lot of time. Maybe 50 days of training. Our aim is to stay focused for these 10 games.
"I don't like to count them down, 10 games, we have to win 10 games. The players have courage. They have personality. We have to have energy, strength, confidence to win every game."Reuse content