The pair played together at Sunderland.
"Jordan has always been a very good player," the Belgian explained to Liverpoolfc.com.
"I remember when I was at Sunderland with him; he was still very young at that time, but everybody saw a very good player in him and everybody saw what he was going to do in the future.
"Everybody saw that he definitely had the talent and that he was going to turn out to be a very good player, even at that age.
"He has matured and is getting a bit older now. You can see how good a player he is, he works really hard and the energy he gives to the whole team is something to be very pleased with."