Slaven Bilic has reinvigorated the East Londoners and narrowly missed out on a trip to Wembley after being held by a late goal against Manchester United at Old Trafford before losing 2-1 in the replay at Upton Park on Wednesday night.
But while Bilic's side must win at the King Power to keep their push for European qualification on track, they know doing so could help their bitter rivals Tottenham Hotspur back into the title race.
Indeed fourth place may not even guarantee West Ham Champions League football should they achieve it such are the permutations in this most wide open of seasons.
Fans torn over approach
Many Hammers fans feel the club should just worry about their own fate and look to continue a fine season by going for a positive result.
But there are a sizeable number who would not complain too much should their side lose and more or less hand the title to Jamie Vardy and co in the process.
In reality West Ham could probably afford to lose and still qualify for the Europa League which would represent real progress.
Not that anyone is questioning the integrity of Bilic and his side who have been brilliant value all season and have lost the fewest games in the Premier League behind the Foxes and Mauricio Pochettino's Spurs.