"We must not forget that Ryan is 20-years-old, he has come from another country and another style of football," said the Reds boss.
"In Holland he was playing as a winger in a 4-3-3 and with the Dutch national team he was a striker, so for him it is difficult to understand everything.
"But he is working hard and trying to learn. Against Cardiff I decided to use him as a striker because I thought it could be good for his confidence and he did okay with Peter Crouch.
"It is the same with Lucas Leiva and Sebastian Leto, they are young players and they need time.
"Ryan's ability to beat players was what impressed me most - he is very good at that.
"He likes to dribble and he likes to shoot. He has pace and power and he knows how to use his strengths and he will be important for us in the future."
