The Argentine forward is unavailable after being laid low by the flu, but he is expected to return in time for Sunday's La Liga derby against city rivals Espanyol
The Argentine has been laid low by the flu, with goalkeeper Victor Valdes also missing the last-16 clash for the same reason.
However, according to Sport, both players are expected to be fit for Sunday’s La Liga derby against Espanyol.
Meanwhile, Andres Iniesta could also be available for the trip to the Estadi Cornella-El Prat.
Spain’s 2010 World Cup final hero has been out of action since damaging the biceps femoris in his left leg in last month’s Copa del Rey rout of Hospitalet.
However, Iniesta, who is training away from the rest of the squad, is reportedly making good progress in his recovery from the muscle tear.
Barcelona could meet Real Madrid if they progress to the quarter-finals of the Copa del Rey, with their great rivals having recorded a 3-2 victory over Malaga in the first leg of their last 16 clash at the Santiago Bernabeu on Tuesday night.