Lucas revealed Rodgers, who replaced Kenny Dalglish last month, made a point of telling him he would have a part to play, and that was a major boost as he fought his way back to full fitness.
He told the club's official website, liverpoolfc.com: "On my first day back in Liverpool, he spoke with me and said I was in his plans.
"Those words helped me to relax a little bit more because he was a new manager coming in and everyone wants to impress. I was coming back from an injury and knew I wouldn't be at the same level as the other players.
"It gave me the confidence to progress slowly and I am really happy to have his support from the beginning.
"When a manager says great things about you, it always gives you extra confidence and motivation - but I was already motivated enough. I am at a big club and very happy to play for this club.
"It's just a question of time and being patient. He has been very important from the first day."