Juventus midfielder Mohamed Sissoko has sustained a hamstring injury, in the wake of his return to action after a lengthy lay-off. The former Liverpool ace made his comeback earlier this season, after spending around seven months on the sidelines with a major foot injury, from which he recovered after having two operations. But after featuring for the Old Lady only in a couple of matches, Sissoko suffered another problem that will keep him out of action nearly for three weeks. Juventus boss Ciro Ferrara was glad to have Sissoko at his disposal, as the 24-year-old forms an influential partnership with Felipe Melo in midfield. Sissoko pulled a hamstring on Wednesday against Sampdoria in a Serie A game. The Mali international was obviously in pain when he made way for Christian Poulsen seven minutes from the hour mark.