Mohammed Kudus will play under Julen Lopetegui, who has been named as the new manager of West Ham United.
The former Real Madrid gaffer replaces David Moyes who has left the club.
Lopetegui is expected to begin his job on July 1 for the start of pre-season, which includes a two-week trip to the United States for matches against Crystal Palace and Wolves.
"I feel very happy, first of all, to be able to be part of the future of this big club," he said.
"We had other opportunities but I am very happy that West Ham chose me because I chose West Ham too, so we are really happy about this.
"I feel that we have a fantastic platform.
"My ambition as a coach is always to be better and better, to achieve more and bigger aims and to encourage and improve the players, the team, and to compete because football is about this – to compete," Lopetegui added.
Kudus, who was a livewire under Moyes will hope to continue his fine form in the next campaign after scoring 14 goals and providing six assists in all competitions for the Hammers in the just-ended season.