The Brazilian winger, on loan from Chelsea this season, was playing brilliantly up until half-time at the Etihad. But Benitez has said that the 22-year-old wasn't feeling well during the break.
"He had some headaches," the Spaniard stated. "He was a little bit down.
"We could see at half time that he was not fine, but he wanted to continue. We could see he was not fine, though."