Benfica will be without Javier Saviola for their Europa League return date with Liverpool on Thursday.
The Argentina international has suffered a broken toe and is expected to be sidelined for up to three weeks.
Saviola has been in scintillating form for the Portuguese giants this season and his absence will be keenly felt by coach Jorge Jesus.
Benfica could also be without commanding centre-half Luisao, with the Brazilian currently nursing a knee problem.
The Samba star is determined to make the game at Anfield, though, with a place in the semi-finals up for grabs.
Benfica will take a 2-1 lead with them to Merseyside, after a combustible first leg in Lisbon, and Luisao believes they have the ability to defend that lead in England.
"We have a really good chance to make the semi-finals," he said.
"We had hoped to keep a clean sheet at home. That was not possible, but we showed our quality by hitting back against a side of Liverpool's stature.
"I don't think either side has an advantage, but Liverpool know they must score and the pressure could be too much for them.
"In this type of game, between two evenly matched sides, anything could happen but I believe it will be us that books a place in the next round."