The former Liverpool defender believes the Spaniard needs competition for his place.
The Reds have been busy this summer, bringing seven new faces to the club ahead of the new season.
One area they have not strengthened is at left-back, with a move for Leicester City youngster Ben Chilwell ending in failure earlier this summer.
It is felt by many that they need to find a replacement for Moreno, who once again struggled last season, with a particularly poor performance in the Europa League final turning fans against him.
And Riise says he can see his former side making a move for a left-back and maybe a few others while they still can.
“I can see Liverpool looking for a left back and maybe a few others as well,” he told Sky Sports.
“I’m a big fan of his [Moreno] but I think he needs more competition. He’s offensive, he’s strong, he’s quick but you can’t get caught out of position that many times.”
It remains to be seen if Liverpool can secure a new left-back before the end of the transfer window.
While Moreno as first choice is concerning, the bigger issue is the lack of competition they have as James Milner is currently filling in as back up.
That is not an ideal situation to say the least and perhaps Klopp will look at more of a back up player than a full replacement for the Spaniard at this stage.