Yoshinori Muto will join Newcastle United from Mainz in a reported £9.5 million ($12.4m) deal pending approval of his application for a work permit.
The 26-year-old forward has agreed terms and undergone a medical with the Premier League club as Rafael Benitez seeks to sew up his fourth signing of the close-season.
But the completion of the move has been delayed until at least next week, when a hearing will be held to determine whether the Japan international is granted a work permit.
Muto featured once for his country at the World Cup in Russia, starting and playing 82 minutes in the 1-0 group-stage loss to Poland.