The Hammers are looking to back new manager Manuel Pellegrini with new signings this summer, with right back Ryan Fredericks arriving from Fulham last week.
More additions will be needed though, particularly at the back, and whilst a deal for Swansea City goalkeeper Lukasz Fabianski is close, a defender appears to be heading for East London too.
Sky Sports report that West Ham have been in talks with Toulouse this afternoon, and have now found an agreement on a £22million fee for defender Issa Diop.
A deal now appears to be imminent for Diop, who has been linked with a whole host of Premier League clubs as the Hammer close in on a coup.
Diop, 21, was born in Toulouse and came up through the ranks of the Ligue 1 side, with more than 80 appearances to his name having made his debut in 2015.
Standing at 6ft 4in tall, Diop is a giant at the back and possesses great strength and aerial ability, as well as enough pace to cope with quick attackers.
West Ham have been desperate for an injection of youth at the back, and Diop fits the bill perfectly with huge potential, and he could become a star under Pellegrini if his expected move does go through.