The Brazilian has been influential in Liverpool‘s improved form since returning to the side in December, but limped out of the Merseyside derby after just 16 minutes.
It’s a major blow for Brendan Rodgers’ side, who face Tottenham, Southampton and Manchester City in their next three Premier League games. Lucas would miss those, plus the FA Cup fifth round tie at Crystal Palace and both legs of the Europa League clash with Besiktas.
Elsewhere, Rodgers says he is hopeful both Philippe Coutinho and Raheem Sterling will be fit to face Tottenham after picking up knocks against Everton. And Daniel Sturridge should make his first start for the club since August.