The Morocco international, who has scored ۲۰ goals in ۶۸ appearances for the Eredivisie side, is poised to become Brendan Rodgers ' third signing of the summer after Fabio Borini and Joe Allen.
Liverpool confirmed the agreement on their official website on Thursday evening, with the ۲۴ - year - old to undergo a medical at Melwood.
Assaidi, who joined Heerenveen from De Graafschap in ۲۰۰۸, has been capped ۲۲ times for Morocco since making his international debut in February ۲۰۱۱.
He has previously been linked with a move to the Premier League with Fulham, as well as Dutch champions Ajax.
