Though he feels that his side has essentially secured its Premier League safety, Palace boss Tony Pulis wants the club to maintain its form and provide real competition.
Following the Eagles' surprise 3-2 win at Everton, the Welshman declared his belief that their 10-point cushion over the bottom three with just four games remaining means that their top-flight survival is secure.
Pulis has built a reputation as a manager who expects nothing less than 100 percent from his players, though. Despite their comfortable position in the table, he is demanding that his charges do not rest on their laurels between now and the end of the season.
"We have a responsibility to the Premier League to turn up for the next four games," the former Stoke City boss told Sky Sports. "I have got great respect for Sam [Allardyce] and West Ham United and then we have got what could be big games against [Manchester] City and Liverpool [still to come].
"I have said to [the players] that it is a fantastic achievement but we have a responsibility to perform in the next four games."
The victory at Goodison Park was Palace's fourth league win in succession, lifting it to 11th place and above Saturday's opponents in the standings.
West Ham, like the Eagles, has climbed away from peril since the turn of the year, with four straight wins in February moving it midtable.
The club has fared less well since then, however, with a run of two victories and five defeats in its last seven matches leaving it in 12th place, seven points above the drop zone.
West Ham's home form has been strong over the last two months, with the team winning four of six games, and manager Allardyce will be keen to improve on that record Saturday and secure three points that should calm any lingering relegation fears.
West Ham was also in action in midweek, going down 3-1 at Arsenal despite taking the lead through Matt Jarvis, and the Upton Park faithful know that a return to winning ways Saturday would see the club climb above its opponent and further aid its bid for a top-half finish.
Captain Kevin Nolan missed the trip to the Emirates Stadium with a hamstring problem and is a doubt for Saturday, as are James Collins (calf) and Joey O'Brien (shoulder). Palace's only doubt is Kagisho Dikgacoi, who missed the game Wednesday with a knock.