Jose Mourinho's side needed a controversial last-gasp penalty from Eden Hazard to draw 2-2 against West Brom before the international break.
That came after a 2-0 defeat at Newcastle the previous weekend and they can ill afford to drop more points against Sam Allardyce's strugglers.
Chelsea lost 3-1 at Upton Park in December last year despite Juan Mata giving them an early lead, but that represents their only defeat in their last 15 meetings with West Ham.
Mourinho will be hoping that striker Fernando Torres is available to return after a leg injury kept him out of the last two games.
If the Spain international is fit, he will vie for a starting berth with Samuel Eto'o. Midfielder Marco van Ginkel is a long-term absentee with a knee injury.
Ashley Cole is also a doubt after aggravating a rib injury during England's defeat to Germany on Tuesday, while Mata and David Luiz will also be hoping for a recall at the end of a week that marks a year since Roberto Di Matteo was sacked.
West Ham, meanwhile, are without a win in their last four Premier League games and sit level on points with third-bottom Fulham.
Allardyce's side have only scored one goal in their last three top-flight matches and have been playing without a recognised striker in recent weeks in the continued absence of club-record signing Andy Carroll.
And the former Blackburn manager knows they will have to be at their best if they are to get the better of Chelsea this time around.
"Anything less than top form for all of our players would make life difficult for us. We will have to produce the end product because chance creation will be harder," he warned.
Allardyce is hopeful James Collins and Joey O'Brien (both hamstring) will be available for selection, but fellow defender Razvan Rat (hamstring) is a doubt.
However, left-back George McCartney is match fit after another spell on the sidelines with a knee injury.
