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'
|MLS Review: Kaka nets in Orlando draw|
|Mexico 1 Ecuador 0: Hernandez, Corona help Herrera´s men to victory|
|Deschamps calls for France response|
|Dunga unfazed by pressure|
|Montenegro fan turns himself in after flare incident|
|Injured Messi not ready - Martino|
|Hodgson: Rooney not close to Charlton|
|Terim proud of Turkey|
|Hiddink happy with point|
|Euro 2016 Qualifying Review: Netherlands and Italy stage late escapes|
|Debutant Eder delighted with Azzurri bow|
|Argentina 2 El Salvador 0: Mancuello nets debut goal in straightforward win|
|Kovac not satisfied despite Croatia victory|
|Netherlands 1 Turkey 1: Huntelaar spares Hiddink from historic home loss|
|Ghana 1 Senegal 2: Konate brace downs Black Stars|
|Bulgaria 2 Italy 2: Controversial debutant Eder rescues Conte´s men|
|Morocco 0 Uruguay 1: Cavani spot-kick seals win|
|Al Sadd say talks with Xavi ongoing|
|McClean slams Sunderland´s handling of poppy controversy|
|Ghana 1-2 Senegal: Black Stars continue Afcon hangover|
|Cheltenham player diagnosed with cancer|
|Palace takeover talk premature - Parish|
|Odegaard becomes Euro qualifiers´ youngest starter|
|Job not done yet, Bale warns Wales|
|Israel 0 Wales 3: Brilliant Bale bags brace as Wales go top|
|Dunga backs Neymar to overhaul Pele´s Brazil goal record|
|League Two Review: Hartlepool climb out of drop zone, Cheltenham go bottom|
|El Salvador 0-2 Argentina: Martino's men triumph without Messi|
|League One Review: Canavan leaves it late to deny County|
|Freddy Adu signs with 11th team in as many years|
|Besiktas deny Cech, Danny rumours|
|Puerto Rico v Canada: Haber targets more momentum|
|Miranda not contemplating Atletico exit|
|Austin relaxed over England prospects|
|Manchester United should sign Ibrahimovic - Schmeichel|
|Ibe eyes Liverpool run-in|
|Bertrand called up by England as withdrawal of four players confirmed|
|A-League Review: Risdon nets stunner, Germano tames Roar|
|Panama v Costa Rica: Unbeaten run a secondary concern for Wanchope|
|Italy coach Conte shaken after death threats - FIGC chief|
|Barca fears over Alba eased|
|Schweinsteiger to start Germany qualifier|
|Akinfeev thanks fans after flare incident|
|Injuries offer Kane chance of first England start|
|Russian Football Union to protest following Montenegro abandonment|
|October comeback the target for injured Foster|
|Van der Vaart looks set to leave Hamburg|
|Bale focused on Wales - Coleman|
|Kluivert helps Curacao to victory|
|Hamstrung Alba returns to Barcelona|
|Macedonia v Australia: Confident visitors eye victory|
|Akinfeev to return to Moscow with Russia squad|
|Brnovic: Montenegro have no chance of qualifying|
|Russia had to resume after Akinfeev incident - Capello|
|Terim: Robben absence important|
|Brazil - Chile Preview: Winning is 'our only option' - Dunga|
|France - Denmark Preview: Olsen hits out at 'disrespectful' hosts|
|Morata keen to keep working|
|Canada 1 Guatemala 0: Haber heads Floro´s men to win|
|Difficult to find a place for Kane in starting XI - Hodgson|
|Difficult to find a place for Kane in starting XI - Hodgson|
|Montenegro-Russia abandoned after scuffle|
|Euro 2016 Qualifying Review: Montenegro-Russia abandoned, Spain and England win|
|Accrington Stanley 0 Newport County 2: Visitors up to sixth|
|Kane delighted with ´dream´ start|
|England 4 Lithuania 0: Kane enjoys dream debut|
|Spain 1 Ukraine 0: Morata settles tight contest|
|Akinfeev struck by flare as Montenegro-Russia game suspended after 30 seconds|
|Brazil v Chile: Winning is ´our only option´ - Dunga|
|Northern Ireland v Finland: Controversial fixture met with religious protests|
|Scotland v Gibraltar: Wilson out to dent countrymen´s hopes|
|Republic of Ireland v Poland: Pressure is on, says O´Neill|
|Georgia v Germany: Schneider warns world champions|
|PSV agree permament Guardado deal|
|France v Denmark: Olsen hits out at training facilities|
|Pienaar to return to Everton training|
|Hughes eyes silverware at Stoke after signing new deal|
|Portugal v Serbia: Carvalho vows to attack|
|Dynamo Kiev stadium partially closed after racism probe|
|Hull City fined £30,000 for misconduct|
|Balotelli must work hard for Italy return – Bonucci|
|Marchisio suffers knee ligament injury|
|Hughes agrees new Stoke City deal until 2018|
|Martinez hopeful over injured Everton trio|
|South Korea 1-1 Uzbekistan: Kuziboyev's debut strike denies hosts|
|South Korea 1 Uzbekistan 1: Kuziboyev´s debut strike denies hosts|
|Japan 2 Tunisia 0: Kagawa and Honda shine as Halilhodzic starts with a win|
|South Africa v Nigeria: Mashaba wary of bitter opponents|
|Japan 2-0 Tunisia: Kagawa & Honda shine in Halilhodzic's first game|
|Parma captain Lucarelli welcomes FIGC reforms|
|South Africa - Nigeria Preview: Mashaba wary of bitter opponents|
|Di Francesco ignoring Milan rumours|
|Melbourne Victory 2 Central Coast Mariners 1: Finkler leads fightback|
|Bale would be ´perfect´ for United - Scholes|
|Badstuber and Bellarabi out of Georgia clash|
|Rooney KOs boxing celebration|
|Allen thrilled with Welsh ´hunger´|
|Kovacic to miss Euro 2016 qualifier|
|Costa Rica 0 Paraguay 0: Dour draw marks Diaz debut|
|Reid ruled out of South Korea friendly|
|Deschamps talks up France despite defeat|
|Rooney chasing England goalscoring record|
|Brazil ´superior´ admit French veterans|
|Reeves sidelined for Finland clash|
|Confidence critical for rampaging Brazil - Dunga|