The Hammers are believed to have had ongoing negotiations to match the asking price for Henry Onyekuru and a bid of around £5.25m is likely to be accepted next week for the teenage sensation.
Onyekuru, who currently plays for Jupiler Pro League side Eupen in Belgium, has been in the squad since 2015 after moving from Senegalese club Aspire on a free transfer.
This season Onyekuru has played just under 40 games, scoring 21 goals and assisting nine times, whilst mainly playing as a left attacking winger.
Chelsea, Southampton and West Brom have all declared an interest, however it is Celtic who have actually offered a bid of £850k back in January 2017.
This bid was turned down as the club valued him a lot more and wanted their player to keep up with the great form.
The Daily Mirror have been keeping a close eye on his movements recently and claim West Ham are the favourites to secure his signature this summer.