The Brazil midfielder has shown glimpses of his potential during a promising start to the season and the boss reckons he will go from strength to strength now he has finally settled into life in England.
"When we played Manchester United, some people came up to me and said Lucas was really good," Benitez told liverpoolfc.tv.
"But when you analyse the situation, you will see that he is a young player who came to a big club like ours. It was different to anything he had ever known and he had no other option but to adapt.
"He has also had to get used to the language, the way of life and it was a problem for someone who had spent all their life initially in Brazil. Yet he shows character every single game and every single day when he is training.
"He works hard, he is always trying to improve. Now we are watching him and we can see he is playing well at this moment in time but we know he is going to keep getting better in the future.
"He is a very good professional and I think that a lot of our fans realise he is someone who gives everything on the pitch for them.
"His confidence is growing, he's trying to take responsibility and he is doing everything. I'm pleased for him and pleased for us because the club is the most important thing."