The 20-year-old, who has been capped once by Brazil at senior level, completed an £8.6 million move from Inter to Anfield on Wednesday.
And, despite the youngster failing to truly establish himself in Serie A, Lucas expects Coutinho to prove a hit for the Merseyside club both now and in the future.
“Coutinho is a very talented player,” he told reporters. “He is very young but he has a lot of experience already.
“I had the chance to watch him when he got his first cap for Brazil a couple of years ago as we were both in the team.
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“He is a proper Brazilian with a lot of skill and he likes to play with the ball and score goals. He had a very good spell at Espanyol when he was on loan last season and I think he will be a great player for the future for us.”
The former Gremio star also expressed his belief that Coutinho will be able to deal with the added physicality of the Premier League.
“I think he will be able to cope,” the 26-year-old continued. "Of course in Italy it’s a different type of game but he has experience of playing in both Serie A and La Liga.
“We hope he settles very quickly. Hopefully he will feel comfortable and play really well for us.”
Lucas went on to reveal that manager Brendan Rodgers had asked him for his thoughts on the player prior to proceeding with the transfer.
“The manager spoke with me but not to ask about his talents as I think he was sure about that already,” he added. "He just wanted to know what I knew about Coutinho as a person. I only had positive things to say.
“Then I spoke with Coutinho a few times. Not to try to convince him to come here but just to tell him about the club and how things work here.
“He felt it was a great opportunity for him to come to the Premier League and we’re happy to have him here. I know he doesn’t speak much English so I will try to help as much as I can to make him feel at home.
“We have Luis, Coates and myself here. We will all try to make him feel really comfortable. We’ll make sure he settles very quickly like Luis and Coates and is able to show his qualities.”