A report on Monday claimed that the Argentine needed a painkiller to play at the Bernabeu after picking up an ankle injury during a training session on Thursday.
Enrique has said that he is against such measures, but insisted that the final decision "rests with the player".
"My recommendations and advice as a manager, are that no player takes painkilling injections, but the decision rests with the player," Inside Spanish Football quotes Enrique as saying.
"As a medical matter, it's something you would have to ask our medics. All I know is that he was 100% fine to play in the game. Medical matters are private to each player."
Barcelona lost 3-1 at the Bernabeu.