The Hammers bolstered their backline by roping in Nayef Aguerd from Rennes earlier in the ongoing window, with Moyes making a fresh centre-back a priority.
Aguerd will add to Moyes’ options at centre-back, which also includes senior defenders Angelo Ogbonna, Kurt Zouma and Craig Dawson, in addition to Diop.
Moyes has made it clear to Diop that he will only be his fifth choice at the club for next season and was open to letting him leave.
Premier League new boys Fulham emerged as Diop’s potential destination as he closed in on leaving the London Stadium.
But according to French radio station RMC, Moyes has now communicated to his club’s deal-makers to press the pause button on sanctioning Diop’s exit.
Moyes wants to wait before he decides whether to give the green light to Diop’s sale, which is a blow for Fulham.
It remains to be seen whether the Cottagers will ultimately get their top centre-back target this summer as his future at West Ham hangs in the air.
