Stoke City forward Marko Arnautovic will undergo a medical with West Ham United on Friday.
The two clubs have reportedly agreed upon a fee of £28m for the Austrian.
Arnautovic has signed a five-year deal, which is expected to make him the club's highest paid player.
Hammers boss Slaven Bilic will welcome his third signing of the summer after the arrivals of Pablo Zabaleta and Joe Hart.