The Brazilian midfielder was forced to leave the pitch after less than five minutes in Liverpool's 2-2 draw with Manchester City on Sunday after sustaining an injury during the pre-match warm-up.
Manager Brendan Rodgers today confirmed the extent of Lucas's injury, revealing that he will miss at least two months of action.
The news comes as another blow to the midfielder, who missed most of last season due to a serious knee injury, from which he returned two months ahead of schedule, and Lucas took to Twitter to air his grievances at this latest setback.
"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," said the 25-year-old.
Lucas will miss key games against the likes of Arsenal, Manchester United, Everton, Newcastle United, Chelsea and Tottenham Hotspur during his spell on the sidelines.