Jurgen Klopp has described Lucas as a "very important player" for Liverpool, despite the Brazilian midfielder being suspended for the team's match against Swansea City in the Premier League this weekend.
The 28-year-old was linked with a move away from Anfield in the summer after struggling for playing time under Brendan Rodgers, but he has started every league fixture since Klopp took charge last month.
The manager told reporters: "I hope he's not a big miss. It's good for both of us that I'm here, I like players like this, he likes playing like this.
"He has improved since we've been here, adapted to our style of player better and better and better. He is a very important player for us. He can be much more dominant in the game, that's what we are always talking about.
"I heard here in England it's 'holding midfielder', we should change this name because [that's] not all of his job. He has to organise, he has to read the game in every situation. I'm not sure how many passes he has to play in this position but it's a lot because usually we have to switch the game. It's an important position in football, in the middle of the pitch it's the heart of the game. And we all know without a heart, nothing works."
Liverpool sit ninth in the table ahead of Sunday's match.
