The Hammers were beaten by two late goals from the now-German champions who ended Bayern Munich’s Bundesliga domination at the weekend.
Xabi Alonso’s side are eyeing a historic double this season after that triumph and they will be desperate to move one step closer to it.
It will be an incredibly tough task for David Moyes’s men to overcome Leverkusen, especially coming off the back of a home defeat to Fulham on Saturday.
Bayer Leverkusen won the Bundesliga title for the first time ever last weekend.
They now sit an uncatchable 16 points clear of Bayern at the top of the table, securing the trophy after beating Werder Bremen 5-0.
Alonso has led his side to glory and denied Harry Kane’s new side their 12th straight domestic success.
Their season has been special and they are still unbeaten, going 42 consecutive games in all competitions without losing.
Leverkusen now have their first piece of silverware since 1993 but they won’t be stopping there as they close in on a second.
If they extend their long unbeaten run against West Ham, they will only be three games away from a second title of the campaign.
West Ham will be without Lucas Paqueta and Emerson who are both suspended.
Jarrod Bowen is set to undergo a very late fitness test to determine whether he can play a part, with his potential absence a huge blow.
Goalkeeper Alphonse Areola, Kalvin Phillips and Konstantinos Mavropanos are all set to miss out with injuries.
As for Leverkusen, Adam Hlozek missed out on their title-winning game at the weekend.
The striker is their only injury concern but the Germans have plenty of cover up front with Patrick Schick and Victor Boniface.
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