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'
|Lovren: Anfield inspired Liverpool|
|Suarez congratulates Liverpool on reaching Europa League final|
|Howe already plotting for next season|
|Griezmann: Who cares if we play ugly?|
|Copa Libertadores Review: Boca, Rosario through to quarter-finals|
|Emery: Sevilla love the Europa League|
|Verratti: I always tell Ibrahimovic to stay at PSG, but he never answers!|
|Marcelino unimpressed by Klopp celebrations|
|Merson wants Koeman at Arsenal|
|´I would not like to be him for one second in my life´ - Klopp slams Marcelino|
|Allardyce: We cannot lose our cool like Tottenham|
|Rashford reminds me of me – Ronaldo|
|£170m windfall for winners of Boro-Brighton clash|
|Martinez: Leicester have not changed English football|
|Marcelino: Liverpool pushed the boundaries|
|City struggled to cope with semi-final occasion - Bale|
|Mahrez wants Leicester stay, says vice-chairman|
|Shakhtar deserved more - Lucescu|
|Klopp hails Liverpool players after ´wonderful night´|
|Sturridge all smiles after returning to lead Liverpool into final|
|Reaching the Europa League final again is a dream - Gameiro|
|Sevilla 3 Shakhtar Donetsk 1 (5-3 agg): Gameiro brace books holders´ third straight final|
|Liverpool 3 Villarreal 0 (3-1 agg): Anfield comeback sends Klopp´s men into final|
|Bologna v Milan: De Sciglio targeting European qualification|
|Leicester players ´love each other´ - vice-chairman Srivaddhanaprabha|
|Simeone rates all-Madrid Champions League final as ´50-50´|
|Eintracht Frankfurt v Borussia Dortmund: Tuchel´s men hope to extend title race|
|Crystal Palace v Stoke City: League points the priority for Pardew|
|Gray determined to prove himself at Leicester|
|Inter v Empoli: Kondogbia wants to end San Siro drought|
|Norwich City v Manchester United: Van Gaal gives United no excuses|
|Olic brands Guardiola a failure|
|Pardew seeks Leicester inspiration for FA Cup final|
|Atletico boosted by Tiago return|
|Casillas rules out Miami switch|
|Sunderland v Chelsea: Larsson eyes crucial victory|
|Dyke confirms Spurs set for Wembley stay|
|West Ham v Swansea City: Payet credits Bilic for impressive Hammers form|
|Fellaini must learn to control himself - Van Gaal|
|Kaka omitted from Brazil´s Copa America squad|
|Gazelec Ajaccio v Paris Saint-Germain: Relegation-threatened hosts eye vital win|
|Leicester City v Everton: Ranieri ready to celebrate remarkable title triumph|
|Stoke´s Joselu slams Toure and Manchester City|
|´We are the champions´ - Shaq sends musical congratulations to Northampton|
|Huth and Fellaini handed three-match bans|
|Lee set for Crystal Palace fine after Pardew remarks|
|AFC Bournemouth v West Brom: Howe feared injuries would curtail Premier League dream|
|Ranieri will not ´break´ Leicester dressing room with star names|
|Pepe: Benitez told me I was not needed|
|Ingolstadt v Bayern Munich: Title in sight for Guardiola´s men|
|Mahrez 50-50 to stay at Leicester - agent|
|Tough to emulate ´inspirational´ Leicester, warns Martinez|
|Bendtner in training at FC Copenhagen|
|Aston Villa v Newcastle United: Wijnaldum demands result to keep survival bid alive|
|Ibrahimovic could make sensational San Siro return - Raiola|
|Obertan, Marveaux released by Newcastle|
|Jovetic wants Toure, Zabaleta at Inter|
|Ramos admires Champions League final rival Simeone|
|Gotze too nice for Bayern Munich ´sharks´ - Augenthaler|
|Bale hits back at Pellegrini ´lucky´ claim|
|Jovetic desperate to earn Inter stay|
|Lucky Madrid no better than Man City - Pellegrini|
|Ferdinand slams City´s lack of desire in Champions League exit|
|Kroos: Madrid have more quality than Atletico|
|Keane: United lack character|
|Klopp: Villarreal in for tough time at Anfield|
|Copa Libertadores Review: Nacional advance to quarters, River eliminated|
|PFA chief wants Leicester stars to be honoured|
|Argentina recall Tevez for initial Copa America squad|
|Keane focused on the Republic of Ireland, not Celtic|
|Ronaldo reiterates desire for Zidane to continue as Madrid coach|
|Keane: City need to improve to win Champions League|
|Falcao left out of Colombia´s Copa America squad|
|Carragher: Sturridge must start against Villarreal|
|De La Hoya´s clanger: ´Whoever thought Leicester would win the UEFA Cup?´|
|Marotta: City asked, but it´s not time to sell Pogba|
|Marcelino wants to turn Anfield atmosphere in Villarreal´s favour|
|Marcelo calls for La Liga focus after Madrid reach Champions League final|
|Origi hopeful of returning before season´s end|
|Madrid were the better side, insists Ronaldo|
|Mangala: City should be proud of semi-final run|
|Madrid move motivated by Champions League glory, says Bale|
|We will leave our soul in the final - Ramos|
|Hart left broken by ´very lucky´ Madrid goal|
|Zidane hails victorious Madrid|
|Pellegrini disappointed to miss out in tie of few chances|
|Real Madrid 1 Manchester City 0 (1-0 agg): Zidane´s men set up 2014 final repeat|
|Lucescu: Shakhtar ready for hardest fight|
|´Benteke cost almost Villarreal´s budget!´ - Marcelino expects major Liverpool test|
|AFC Champions League Review: Big-spending Jiangsu Suning dumped out|
|Kompany off injured in Champions League semi|
|Ter Stegen: I want to stay at Barcelona|
|Vardy will thrive for England at Euro 2016, says Smith|
|Lemina eyes key role at Juventus|
|Cerezo hits back at Vidal´s ´ugly´ swipe|
|Bacca happy at Milan without European football, says agent|
|Long backs Saints to end Spurs hoodoo|
|West Ham´s Sullivan labels Leicester lucky|
|Alba admires Atletico team work|
|Ranieri deserves an honour - Italian prime minister|
|Klopp bullish ahead of semi-final showdown|
|Ranieri´s 96-year-old mother: Now my son is King of England|
|Lovren: Europa League final would save Liverpool´s season|
|BREAKING NEWS: Dembele set for long FA ban over Costa altercation|
|AC Milan ultras call for Galliani´s head over ´blatant mockery´ of fans|
|Emery wants ´inspired´ Konoplyanka in Europa League semi-final|
|Wendell Lira blames Puskas Award trip for club woes|
|Joe Cole in line for Tampa Bay Rowdies move|
|Fuchs: I could kiss Hazard after title-clinching goal|
|Hiddink turned down Leicester before Ranieri appointment|
|Arsenal did not hold their nerve in title race - Smith|
|Cazorla targets City comeback for Arsenal|
|Webb could face lifelong ban as FIFA opens proceedings|
|Smith backs Leicester to become Premier League ´force´|
|Toni to retire after Juventus clash|
|Iwobi reveals key to dream Arsenal rise|
|Allen expects to reach Europa League final|
|McLeish leaves Zamalek after 65 days|
|Football fans pile bets on Burnley to win Premier League after Leicester´s shock success|
|Ranieri: Rich teams will win for next 10 to 20 years|
|Pity we could not reward Guardiola for his three years, says Bayern captain Lahm|
|Madrid revenge no factor for Simeone|
|Copa Libertadores Review: Pumas UNAM, Atletico Nacional advance to quarter-finals|
|Adelaide want Leicester City friendly|
|Tottenham have proven critics wrong - Eriksen|
|Ferdinand ´turned on´ by Simeone´s Atletico|
|Wilson hoping Brighton experience enough for United|
|Griezmann urges team-mates to keep feet on the ground|
|We´ve learned from past errors - Fernandinho|
|Payet cleans up West Ham awards|
|´We don´t need superstars´ - Ranieri|
|Vidal: Bayern are still the best in the world|
|Guardiola: I have given my life to Bayern|
|Simeone: Atletico have eliminated two of the world´s three best teams|
|Leicester owner reveals Vardy signing doubts|
|Bayern feel cheated, says Rummenigge|