Chelseaâ€™s 3-2 loss to Rubin Kazan still saw them squeeze into the Europa League last four.
"Fernando did really well," Benitez said.
"He's been doing well in the last games, he's working hard, he's creating chances for himself and his team-mates.
"We will think what we have to do for Sunday. Still we need to check how Demba is and afterwards we will decide."