Eden Hazard admits Chelsea have no margin for error as the Blues try to remain in control of the race to qualify for the Champions League.
Rafael Benitez's side, fourth in the Premier League, host London rivals West Ham on Sunday with victory essential to keep ahead of fifth placed Arsenal and in touch with third placed Tottenham.
By the time Chelsea kick off this weekend they could be only two points in front of Arsenal, if the Gunners win at Swansea on Saturday, and Belgian playmaker Hazard is aware the pressure will start to mount on his team if they slip up against the Hammers.
"Three points are a must for us on Sunday, we need to win the match," Hazard said.
"Chelsea are a big club. We have to win titles and to qualify for the Champions League. There's a lot to do but we'll try to do it all."
After months of abuse from Chelsea fans, interim boss Benitez is no closer to winning over the Stamford Bridge faithful judging by the empty seats and poisonous atmosphere that provided the backdrop for Thursday's Europa League win over Steaua Bucharest.
But, despite the constant sense of chaos surrounding Chelsea, the team are still in with a chance of winning the Europa League and FA Cup.
They face an FA Cup quarter-final replay against Manchester United and a Europa League last-eight clash with Rubin Kazan, meaning Benitez's men face six games in 16 days.
The international break which follows Sunday's derby will offer a pause for breath, but first Chelsea will seek to cement their place in the top four and Hazard hopes the lack of recent action for West Ham, who will be playing just their second match of the month, can benefit his team.
"It might favour us at the start of the game because we should be able to set the tempo and get into our stride quicker because we've been more used to playing competitive games recently," Hazard said.
"But where it might favour them slightly is the fact that towards the end of the game tiredness may set in for us, while in effect they should be stronger because they've had a bit of a rest.
"It's something we have to deal with, and with the support of our fans behind us I'm sure we will be able to."
Chelsea suffered the first defeat of Benitez's reign at Upton Park in December, throwing away the lead in a 3-1 loss, and it is a painful memory for Hazard, who concedes his team-mates will have to be far more switched on if they want to avoid a repeat.
"At Upton Park, one or two errors crept in, particularly during the second half, but we were very good in the first half," Hazard said.
"We need to try to repeat that first-half display on Sunday and make sure we get a positive result. We are going into the game in good form, so we should be able to produce a strong performance."
Sunday's trip across London to face Chelsea will be one of only three fixtures for West Ham throughout March due to their FA Cup elimination and the international week.
Hammers boss Sam Allardyce, who will be without midfield trio Kevin Nolan, Mark Noble and Joe Cole, concedes it is a far from ideal situation.
"We knew the situation," he said. "All we can do is do what we did last time we played and try to win because then it makes the two weeks pretty pleasurable to get through.
"We have got exactly the same situation on Sunday when we have two weeks again before we play West Brom and we have got to try and handle it the best we can.
"I would rather have played last weekend but I'm not sure about Chelsea playing Thursday night and Sunday because that is the hardest thing to overcome."