The 24-year-old joined the Reds from Heerenveen last year, but he struggled to make an impact at Anfield and made just 12 appearances in all competitions.
Following reports that Liverpool boss Brendan Rodgers would be prepared to sell the Moroccan, Koeman has admitted that the winger would be welcome at De Kuip.
"I hope that [the deal] comes around soon. Assaidi is a player who can play in different positions - we just have to wait and see whether this is feasible," he is quoted as saying by AD.
FC Twente are also thought to be monitoring Assaidi's situation.