West Ham will have to make a permanent move in order to sign Marseille defender Duje Caleta-Car this month.
Marseille are open to letting centre-back Caleta-Car leave but, heading into the final week of the window, insist they are no longer willing to sanction a loan exit for the 25 year-old.
Caleta-Car has also been linked with Newcastle, Wolves and almost joined Liverpool a year ago. He has 18 months left on his contract and is valued at around £15m by his French club.
Caleta-Car has been on West Ham's radar for some time including last summer before they clinched the signing of Kurt Zouma from Chelsea.