West Ham have agreed a fee of 40m euros (£33.5m) including add-ons for Lille midfielder Amadou Onana.
The Hammers are looking to bolster manager David Moyes’ squad before a second consecutive European campaign.
However, the deal for Onana, 20, is not completed yet and personal terms are still to be agreed for the player.
The Hammers are also interested in signing Burnley playmaker Maxwel Cornet, 25, who scored nine goals in 26 games for the Clarets last season.
Dakar-born Onana was capped at youth level before making his senior Belgium debut in a 4-1 Nations League defeat to the Netherlands in June.
The 6ft 5in (1.98m) prospect began his youth career at Belgian clubs Anderlecht, RWS Bruxelles and Zulte Waregem before spending three seasons with Hoffenheim’s academy.
Onana signed for Hamburg before the 2020-21 season and swiftly established himself as a first-team regular for the German second-tier side.
After joining then-French champions Lille in August 2021, Onana made 31 appearances in Ligue 1 last season and featured in all of the club’s Champions League matches, starting in a 2-0 defeat at Chelsea in the first leg of their last-16 tie.
West Ham are set to make Onana their fifth signing of the close season following the arrivals of goalkeeper Alphonse AreolaMILF midfielder Flynn Downesdefender Nayef Aguerd and forward Gianluca Scamacca,