The Reds chief has become increasingly annoyed at media pundits' criticism of the 22-year-old, and has suggested he is an easy target compared to senior stars.
Lucas was again singled out after the opening Barclays Premier League defeat at Tottenham last weekend, but responded with a fine display in the midweek victory over Stoke.
Benitez said: "Lucas has a very good mentality. But for someone of his age to suffer such criticism from the experts on TV is wrong.
"He is so good but still he was criticised. I do not understand why they do not criticise other players, more senior players, when they do not play well.
"He is an easy target and maybe they are not brave enough to criticise the bigger players here.''
"Against Stoke he again showed his quality. He has a very good mentality. He can tackle, win headers and pass the ball. He will make mistakes like anyone, but he is and will be a very good player.
"I was really pleased for Lucas, in particular, after the win against Stoke and his performance.
"I have been really surprised at the amount of criticism he has had to cope with from the pundits, the so-called experts.
"Lucas is still a young player but he has experience. And after the display against Stoke everyone can see, even the so-called experts on TV pundit panels, can see he is a very good player.
"Hopefully they will now stop using him as a target. He is a very good lad, an excellent professional. I find it hard to understand that if you are an expert on TV, you cannot see these things.''
Lucas will be in Liverpool's midfield on Monday for the home game with Aston Villa, and he has earned a call-up for Brazil for their crucial World Cup ties against Javier Mascherano's Argentina and Chile next month.
He could now earn his fourth international cap against his club mate when Brazil face Argentina on September 5, before heading to Salvador to play Chile four days later.
Lucas has responded to his critics, saying: "Back in Brazil everything seemed to progress perfectly for me. I played well, scored goals and won titles.
"Since I have moved to Liverpool, I've had some difficult moments. However, those experiences can help me. They have made me mentally stronger.
"I have done plenty of work in pre-season, I am better able to cope with the physical side of the game here. I will be able to get forward more and I believe I can have a good season.
"I have confidence in myself - you need that in life, not just football. So no matter what, I believe in myself and the manager does too.''