Chelsea defender Ricardo Carvalho has been ruled out of his side's UEFA Champions League semi-final second leg against Liverpool on Tuesday after sustaining a knee injury. The Portuguese defender limped off the pitch during the first-half of Chelsea 2-2 draw with Bolton Wanderers in the Premiership on Saturday. Blues' boss Jose Mourinho was left to rue his bad luck which would cost the team their place in the Champions League final. "He's out for Tuesday. Our best defender for the whole season - how big a blow is that," Mourinho was quoted as saying by Chelsea's official website. "We lost in Liverpool without him in the Premiership and we play again there without him. Last time we had to play with Paulo [Ferreira] at centre-back but in this moment we have better options than to play Paulo at centre-back."' The English champions will be looking to maintain their one-goal advantage when they visit Anfield Road on Tuesday.