Liverpool midfielder Lucas Leiva is expected to be sidelined for up to two months by a knee ligament injury. It is understood the Brazil midfielder has damaged the medical collateral ligament in his right knee. Although not as serious as injury to a cruciate ligament - the 27-year-old ruptured the anterior cruciate ligament in his left knee in November 2011 - it will still keep the midfielder out for six to eight weeks, which would take him into March. Lucas sustained the injury just 20 minutes after coming on as a half-time substitute in Saturday's 2-2 draw at home to Aston Villa. He told manager Brendan Rodgers he heard 'a click' in his right knee following a challenge with Fabian Delph and subsequently left the ground on crutches, later tweeting: 'It is in God's hands.' Lucas had been left out of the starting line-up as Rodgers opted to play captain Steven Gerrard in a holding role for the second successive match, allowing him to field a more attacking side with returning striker Daniel Sturridge accommodated at the Brazilian's expense. The experiment did not work and Rodgers corrected his mistake at half-time and Lucas' arrival did allow the Reds to regain some control.