West Ham have agreed a fee with Bayern Munich for Moroccan full-back Noussair Mazraoui.
Sources say if the deal goes through, the Hammers will play an initial €16m (£13.47m) for the 26-year-old, with a potential further €3.5m (£2.95m) in add-ons.
Talks over personal terms are continuing for a player who has been linked with a number of clubs this summer, including Manchester United.
Mazraoui was born in the Netherlands and joined Ajax as a youngster.
He joined Bayern on a free transfer in 2022 and made 29 appearances for the Bundesliga giants in all competitions last season.
Meanwhile, the Hammers remain in talks with Aston Villa over striker Jhon Duran.
Villa are prepared to let the striker, who joined from Chicago Fire for around £18m in January 2023, leave.
He has made just three Premier League starts and has been open to finding a new club.