Sam Allardyce has billed West Ham's home clash with fellow Premier League strugglers Sunderland on Saturday as "critical".
The London club were consigned to a 4-1 hammering at Liverpool last weekend and have now lost four of their last five top-flight matches.
That dismal run has left them languishing perilously above the relegation zone, level with Fulham and Crystal Palace - who are 18th and 19th respectively - and five points clear of Saturday's opponents.
Bottom-of-the-table Sunderland have picked up just two points on their travels in the Premier League this season, though, and West Ham boss Allardyce is not playing down the importance of his side's encounter against Gus Poyet's team.
He said: "It's a critical game for both teams. Both teams need to win and listening to Gus' quotes that's their objective.
"Every team in the Premier League can be difficult to break down and most games are decided by a bit of luck or mistakes that you make.
"We need all the lads that are available to step up to the plate and try and repeat the Fulham performance and get the same result."
Allardyce will have to do without skipper Kevin Nolan, who starts a three-match ban following his red card at Anfield, but fellow midfielder Ravel Morrison returns from suspension.
Defender James Tomkins (hamstring) will undergo a fitness test ahead of the match, but Allardyce expects James Collins and Guy Demel to be available despite being unwell this week.
Stewart Downing (leg wound), Winston Reid (ankle), Andy Carroll (foot), Mladen Petric (calf), and Ricardo Vaz Te (shoulder) are definitely out.
Sunderland are rooted to the foot of the table with only eight points from 15 games, and Tottenham condemned them to a third defeat in their last four last weekend.
Poyet's honeymoon period at the Stadium of Light is over, and the Uruguayan is eager to secure Sunderland’s first away win of the season at Upton Park.
"We know what we are coming up against and how difficult it will be," he told the club's official website.
"We need to stand up and do the right things all the time, be very strong as a group as well as being brave on the ball and making things difficult for them.
"Then, you always have a chance to win. We need to start winning games and we’ve got another opportunity on Saturday."
Poyet will be hoping Carlos Cuellar (hip) is available for the trip to London, but goalkeeper Keiren Westwood (shoulder) remains doubtful.
|Coach: S. Allardyce|
for M. Jarvis 56'
for G. Demel 58'
for J. Cole 75'
|Relegation run-in favours Leicester - Walsh|
|Fiorentina v Dynamo Kiev: Pasqual calls for response in second leg|
|Schmidt extends Mainz deal|
|Parma on the market for €20million|
|Zenit v Sevilla: Villas-Boas wary despite key player returns|
|Title a step too far for United, says Evans|
|De Bruyne agent reveals Manchester City talks|
|Kroos not making excuses about absences|
|BREAKING NEWS: Smalling signs new United deal|
|Depay like a young Ronaldo - De Boer|
|Napoli v Wolfsburg: Benaglio eyes return to form|
|Frontzeck: Survival fight is not about me|
|Real can cope with injuries - Ancelotti|
|Dnipro v Club Brugge: Preud´homme prepares to show his hand|
|Silva returns to training after cheekbone scare|
|Villa and Reading charged over alleged FA Cup crowd trouble|
|Zeman resigns from Cagliari post|
|Opportunity knocks as Dyche plans for Barnes absence|
|Berbatov dreaming of Champions League semi-final|
|Benzema joins Real´s injury list|
|Jenkinson: West Ham will not settle for mid-table|
|Montella calm over fan frustrations|
|Blanc: Barca are the model for PSG|
|Newcastle just need three more points - Janmaat|
|Gaya: Six finals left for Valencia|
|Muller wary of Porto counter-attacks|
|Bartomeu plays down Pogba link|
|Verratti hails ´essential´ Ibrahimovic|
|Zidane backs PSG to upset Barca|
|America v Montreal Impact: Klopas unfazed by host´s form|
|Vlaar open to Villa stay|
|Shepherd urges fans not to boycott Newcastle|
|Maritimo 1 Nacional 1: Tiquinho ensures derby finishes all square|
|Fiorentina 0 Verona 1: Diamanti and Neto pay the penalty|
|Elche 1 Real Sociedad 0: Bergara gifts win to hosts|
|Van Persie returns in Under-21 game|
|Turkish Super Lig Review: Galatasaray slip sees Fenerbahce go top|
|Russian Premier League Review: Arsenal Tula and Rostov maintain survival bids|
|Frontzeck named as Korkut´s replacement at Hannover|
|Lopetegui wary of Bayern backlash|
|Pastore plays down Cantona´s world best tag|
|PSG absences no excuse for failure - Blanc|
|Suarez sad to see Gerrard leaving Liverpool|
|Cleber injury adds to Hamburg woes|
|Northern Ireland free to play Romania at Windsor Park|
|Juve sweating on Vidal availability|
|Monaco v Juventus: Evra ready to take control|
|Striking concerns for Chelsea after Drogba injury|
|PSG and Chelsea have bid for Dybala, claims agent|
|Pogba can leave Juve for ´right offer´|
|Bendtner dropped after arriving late for training|
|Messi achievement unrepeatable, says Luis Enrique|
|Football League Preview: Preston and MK Dons battling to join Bristol City|
|Real Madrid v Atletico Madrid: Ancelotti optimistic amid injury concerns|
|Iniesta declared fit for PSG second leg|
|Bale remains a doubt for Atletico clash|
|Schweinsteiger set to face Porto, Ribery to miss out|
|No broken cheekbone for Silva|
|Final appearance can remove negativity at Villa - Fox|
|Bale selected in Football League Team of the Decade|
|PSV director: United and PSG want Depay|
|Korkut sacked by relegation-threatened Hannover|
|Sherwood: Pressure all on Arsenal|
|Newcastle in a ´dangerous moment´ - Colback|
|Kovac hopes to have Modric fit for Euro qualifier|
|Copa Libertadores Preview: Cruzeiro boss Oliveira does not fear sack|
|MLS Review: Revs extend unbeaten run, Timbers stun City|
|Fournier proud and disappointed|
|Shaw ready to make an impact|
|Hazard among best three in the world - Mourinho|
|Carver: Newcastle are in relegation battle|
|CAF Champions League Review: Setif get two away goals, Al Ahly denied late on|
|Inzaghi praises Milan derby officials|
|La Liga Review: Granada frustrate Sevilla, Villarreal´s woes continue|
|Inter should have had a penalty, Mancini fumes|
|Ligue 1 Review: Lyon return top after derby draw|
|Inter 0 Milan 0: Disappointing derby ends in stalemate|
|Primeira Liga Review: Sporting made to battle, Penafiel running out of time|
|Balotelli targets officials in latest social media outburst|
|Bundesliga Review: Werder Bremen edge Nordderby, De Bruyne rescues Wolfsburg|
|Serie A Review: Napoli close on stumbling Roma|
|Pochettino congratulates 30-goal Kane|
|Rodgers questions Liverpool´s mental strength|
|Carver counting on experience after latest defeat|
|Sherwood marvels at Grealish potential|
|Eredivisie Review: Dordrecht relegated as Go Ahead Eagles stun Feyenoord|
|Newcastle United 1 Tottenham 3: Losing streak continues amid fan boycott|
|Kouyate elbow on Silva accidental - Allardyce|
|Aston Villa 2 Liverpool 1: Delph ends Gerrard´s hopes of dream farewell|
|Pellegrini hails City response to derby defeat|
|Silva back home after Kouyate elbow|
|Manchester City 2 West Ham 0: Silva injury sours routine win|
|Bayern Munich v Porto: Neuer rallies Germans for uphill battle|
|Barcelona v Paris Saint-Germain: Marquinhos keeps the faith ahead of Camp Nou test|
|Fer closes in on QPR return|
|Crouch set for surgery|
|Dortmund confirm Tuchel as Klopp replacement|
|Adams leaves relegation-threatened Tranmere|
|Real still unsure over Modric injury|
|Tevez rubbishes Juve exit talk|
|Moyes: I had to fight to keep Rooney at United|
|Perth Glory 3 Melbourne City 1: Maclaren treble the difference|
|Dyche: Burnley are too honest|
|Illarramendi eager for Real stay|
|Hazard issues Chelsea warning|
|MLS Review: Injury-time winner buoys Galaxy, Martins shows class for Sounders|
|Pastore talents ´unpredictable´ - Blanc|
|Liverpool much bigger than City - Rodgers|
|AFC Champions League Preview: Evergrande look to progress|
|Clarke expects distraught Federici to bounce back|
|Toure is City´s scapegoat - agent|
|Allegri praises high-flying Juve|
|Athletic Bilbao 4 Getafe 0: Hosts end winless run|