The Brazil international's season has been curtailed by a cruciate knee ligament injury sustained in the Carling Cup quarter-final victory over Chelsea in midweek.
Lucas has been one of the Reds' best players over the last two seasons and in the last fortnight, in particular, the 24-year-old has shown his worth with impressive performances against Chelsea in both the Barclays Premier League and Carling Cup wins and also in the 1-1 draw at home to Manchester City last Sunday. It leaves a hole in central midfield which will take some filling.
"It is a huge disappointment for everybody but more importantly for Lucas," said Dalglish. "He's had the scan and we will assess it and decide where is the best place he has to go and where he is more comfortable and they'll do what they have to do.
"We have a great deal of sympathy for Lucas. He's been playing well for us but it is part and parcel of football I suppose. We're not the only club who has an injury which means we have to fulfil our obligations by using the squad."
He added: "He has been playing really well. We are disappointed he has picked up an injury but it is not career-threatening. Lucas is not moping about feeling sorry for himself. We can do that, we can feel sorry for him. But we cannot feel sorry for ourselves and we have plenty of people who can have a go and won't let us down. You saw at Stamford Bridge on Tuesday night there were a lot of really good performances. It is at times like this you are tested but we have been happy with the squad and the results we have had reflect that."