Crystal Palace manager Sam Allardyce has indicated that it will be difficult to sign Mamadou Sakho from Liverpool on a permanent basis as there is no clause in his loan agreement.

The centre-back arrived at Selhurst Park in January after being exiled from Liverpool's first team following a disciplinary issue.

Despite not having a minute of Premier League action under his belt, Sakho has been a solid addition to the defence, making six top-flight appearances and helping keep four clean sheets.

Allardyce has hinted that the club will consider trying to get a permanent deal, but it will not be easy.

In Friday's press conference, the manager told reporters: "No clause to make Mama's stay permanent, but it was a great deal getting him in. We can't talk about that until we're safe."

Sakho recently suggested that he wants to revive his Liverpool career.