Ghana international Mohammed Kudus was absent from West Ham's UEFA Europa League game against Bačka Topola on Thursday night due to illness.
The 23-year-old attacker did not travel with the team to Serbia for the match, which West Ham won 1-0 thanks to a late goal by Tomas Soucek.
Kudus has been in excellent form for the Hammers since joining the club in August, scoring five goals and providing one assist in 16 appearances across all competitions.
He has started ten of those games, including the recent 2-1 win against Burnley, where he scored a late equalizer to help his team come from behind and secure the victory.
The absence of Kudus was felt by West Ham, who struggled to create clear-cut chances against Bačka Topola. However, the team's victory ensured their qualification to the knockout stages of the Europa League.
It is unclear how long Kudus will be sidelined due to his illness, but West Ham will hope to have him back in action soon as they continue their push for success in both domestic and European competitions.