"This year, Peter is more mature and he needs to understand what it means to be a Liverpool player," said the Liverpool boss.
"People were talking before he signed that he wasn't good for us. But after a while he was in the squad with the national team and now people know how good he is.
"But he cannot think that is enough. He now needs to continue improving as he has a lot of potential and possibilities.
"You cannot stop improving. He needs to know how important it is to score goals, to make assists and to work hard for a club like this, and I think he is going about things the right way.
"He needs to improve in some areas and keep doing the things he has done well."