The 24-year-old Senegalese defender, who is also capable of playing a midfield role, is expected in London this afternoon before signing a four-year deal with the Hammers.
It was believed the defender would opt for a move to La Liga, with Valencia the favourites for his signature for a long time. But the Hammers look like they’ve managed to win the race for the highly-rated youngster.
It will be the first serious West Ham signing since Hammers boss Sam Allardyce was handed a brutal ultimatum from owners David Gold and David Sullivan, who have ordered him to start playing more attractive football or face the boot following a disappointing season in the Premier League.
And such demands have been followed up by the arrival of Teddy Sheringham as attacking coach and former Birmingham City striker Mauro Zarate, who joined on a free two weeks ago.
It is believed Gold and Sullivan have taken the club’s transfer policy in to their own hands following a number of dubious arrivals under Allardyce’s watch, and they look set to get their man following weeks of speculation.