The Brazilian defensive midfielder limped off in the early stages of Liverpool's Premier League game against Manchester City on Sunday.

Lucas picked up the thigh injury during the team's pre-game warm-up, but started the game regardless, lasting just four minutes before being replaced by Jonjo Shelvey.

The injury is a huge blow for Lucas, who only recently returned from a cruciate ligament injury that caused him to miss the second half of last season.

"(It) looks like Lucas will be out for a few months. Early indication is he will be back after 2-3 months out," Rodgers told reporters at a press conference ahead of Liverpool's Europa League second-leg tie with Hearts.

Rodgers is, however, optimistic that Lucas can make a quick recovery from the injury.

"He is a quick healer so I expect him to be back sooner than that," he said.

Lucas will miss a number of important fixtures for Liverpool, including a visit from Manchester United and the Merseyside derby.

The Brazilian took to Twitter to reveal his disappointment at picking up another serious injury.

He wrote: "No words to describe my feelings at the moment. It is been hard to be positive but I am sure better days will come. YNWA."