The Brazilian midfielder suffered a cruciate knee ligament injury in a November 2011 clash with Chelsea but made his return in pre-season training at Melwood this week.
And the 25-year-old says he must now be patient in order to match the level of performance which saw him become a key man for the Reds.
"I'll be back at the same level that I was because I am working really hard to recover and the players that I have beside me will help me," Lucas told reporters.
"I just have to be patient again; much of my life in Liverpool has been like that.
"I'm still in the progress of my rehab. I've been training with the team for a few days. There is still a long way to go and a lot of work to be done but I am very happy to be able to train and I'm looking forward to the new season.
"I will be trying every week to recover and to progress. It's still four or five weeks until the start of the season and our Europa League games, so it's still too early to say if I will be ready but I'm looking forward to starting the season and being able to play.”
The former Gremio man also admitted that it was extremely difficult to watch his team-mates play from the sidelines last season.
"It's always hard to watch from the television, especially at a time when I was really enjoying my football and playing with a lot of confidence," he added
"It was hard because I've never had an injury like that and I hope I won't have again.
"So I'm just training everyday and seeing how I feel. I'm improving, I think that's the main thing now and hopefully I will be okay for the rest of the season."