David Moyes wants to bring in two midfielders to replace Arsenal-bound Declan Rice and Zakaria is one of the primary targets.
West Ham have been in talks with Juventus for a while in their pursuit of the midfielder but no agreement is in place.
Moyes is keen to bring in fresh reinforcements soon this summer but negotiations for Zakaria have dragged on due to a key difference between the two clubs.
And according to journalist Ignazio Genuardi, the two clubs are yet to agree on the key aspect of the purchase clause.
Juventus are ready to agree to loan him but want to include a mandatory purchase clause in the agreement.
However, West Ham are still not ready to accept that condition and are pushing for a loan with an option to buy.
Juventus want guarantees about Zakaria’s departure as Chelsea opted against taking up the option on him this summer when the loan stint expired.
