The Portuguese international was forced out of the action after just 19 minutes of the Carling Cup second round tie, with the injury following a clash with Exeter defender Danny Coles.
"Raul has hurt his collarbone. I don't know what the technical term is but he fell heavily," said Kenny Dalglish after the game.
"He will come back with us and we will see how long it is before he is back.
"We don't know how serious it is but it'll be a few weeks.
