At 34 years old, Kandolin is reuniting with West Ham's manager, Graham Potter, whom he worked with at Ostersunds from 2015 to 2018. During their time together, the pair developed a strong working relationship.
Kandolin will start working with his new colleagues when the first-team squad returns to Rush Green for pre-season training next week. He takes over from Xavi Valero, who recently left West Ham to join Liverpool.