The Blues' hopes of securing Champions League football are fading fast, with Antonio Conte's team having fallen eight points behind the top four, and they are up against a Hammers side still fighting for their top-flight future.
Chelsea owner Roman Abramovich would have baulked at the thought of Europa League football at the beginning of the campaign, but last weekend's 3-1 defeat to Tottenham Hotspur has made that a very real possibility next season.
The Blues first loss at home to Spurs since 1990 has left them firmly in fifth place in the table, eight points behind their London rivals and five ahead of Arsenal directly below them, with seven matches left to play.
As far as the Russian and manager Conte are concerned, one of the most troubling things about the club's predicament is the current run of form they are on.
Five defeats in the last seven league matches is Chelsea's worst run since that abysmal spell during the 2015-16 season which cost Jose Mourinho his job.
There was only one positive to pick from the bones of last weekend's home humbling: a goal for Alvaro Morata, marking the first time the Spanish hitman has netted in back-to-back fixtures since December.
Nevertheless, 2018 has so far been a year for Blues fans to forget, with their team having won just seven of 19 matches this calendar year, and two of those victories came via extra time or penalties.
During that run, they have crashed out of the Champions League at the last-16 stage, beaten over two legs by a much-fancied Barcelona side, but FA Cup glory could be a potential silver lining in an otherwise disappointing season, as the Blues are into the last four of that competition.
Conte is almost certain to leave Stamford Bridge at the end of the season - even an FA Cup triumph will not change that - and the question marks surrounding his future could well hang heavy when West Ham make the short trip across London.
Recent form in Premier League: LWLLWL
Recent form (all competitions): LLWLWL
West Ham United
West Ham's season hit a low point last month when ugly fan protests marred their 3-0 home drubbing at the hands of Burnley.
That was a third defeat on the spin for David Moyes's side, but the Hammers have since stopped the rot with a vitally-important victory in last weekend's six-pointer against fellow relegation battlers Southampton.
Marko Arnautovic's first-half brace and Joao Mario's opener in that fixture helped West Ham put breathing space between themselves and the dropzone, moving them up to 15th place, but with only five points between them and the Saints in 18th, a defeat at Stamford Bridge could put them back in immediate danger.
A big plus to draw from the win over Southampton was the return of Arthur Masuaku from a spitting ban. The winger proved instrumental when the Hammers played Chelsea at the London Stadium earlier in the season and is expected to retain his place against the Blues.
Overall, the Hammers' form is sketchy at best, with that victory over the Saints being only their second in the last nine matches.
Moyes's men conceded a whopping 11 goals in the three matches preceding that one, a tally that has contributed to them having the second-worst defence in the division.
Going forward, their haul of 39 goals for an average of 1.22 per match is middling, the 10th-best in the Premier League and identical to what Bournemouth have managed.
Moyes is out of contract at West Ham in the summer, but a positive result against Chelsea will keep them on course to retain their top-flight status, and thus take the Scot a step closer to scoring a new deal.
Recent form in Premier League: LWLLLW
West Ham could welcome back attacking midfielder Edimilson Fernandes for the trip to Stamford Bridge.
The Swiss international is targeting a return to first-team football after four months out with an ankle injury, but may have to settle for a spot on the bench as Moyes is unlikely to tinker with the side which beat Southampton so convincingly.
The big news for Chelsea is a potential return for goalkeeper Thibaut Courtois, with the Belgian international likely to replace Willy Caballero between the sticks if passed fully fit ahead of kickoff.
Conte has been tipped to blood youngsters in his remaining games, including 17-year-old forward Callum Hudson-Odoi, while January signing Ross Barkley is said to be on the verge of the Chelsea first team after featuring for the club's reserves last weekend.
Chelsea possible starting lineup:
Courtois; Azpilicueta, Christensen, Rudiger; Moses, Fabregas, Kante, Alonso; Willian, Morata, Hazard
West Ham possible starting lineup:
Hart; Rice, Ogbonna, Cresswell; Zabaleta, Kouyate, Noble, Masuaku; Antonio, Arnautovic, Joao
Head To Head
Moyes's first win at the Hammers helm came against Chelsea earlier this season, with an early Arnautovic goal proving the difference between the two sides when they met at the London Stadium in December.
While West Ham fans would love a repeat of that scoreline, they should also be grateful if they manage a draw, as the Hammers have fared poorly at Chelsea over the years.
They are winless in their last 11 trips to Stamford Bridge and haven't beaten the Blues there since way back in 2002, pulling off a 3-2 victory in September of that year.
Overall, this fixture has been played 109 times competitively and was first contested in 1923.
Chelsea have only a marginally better record than West Ham, winning 49 of those games, losing 40 and drawing the same number.
We say: Chelsea 1-0 West Ham United
This will be a close game between two sides with recent troubles hanging over them, and while West Ham will head into the match in a more positive mindset following last weekend's win against Southampton, Chelsea have the quality to reverse their recent fortunes. There are signs that Morata has started firing again and with key players like Courtois back in contention, the Blues are unlikely to lose a second London derby on the spin.