The Liverpool hitman has not played since limping out of the first leg with a twisted ankle.
And boss Rafa Benitez admitted: "We have to decide if he is fit and if he can play. But I won't look at Saturday's game, just how he feels for Real.
"We need to decide if he can do 90 minutes, or if it would be better to keep him on the bench.
"There is another training session to go, so we'll talk after that."