Keane also wonders if Evra is the club's best solution at left-back.
He wrote in The Sun: "Patrice Evra needs to show more leadership and Nani has to give more, certainly more than he did on Monday night.
"I've got my doubts about Evra. He's been captain since Nemanja Vidic was injured but he needs to stand up and be counted in big games.
"One or two players were going past him too easily against City and he has to get the players around him playing more than they do. "