The England hitman struggled for form at the start of the season and Fergie admitted Rooney needed to up his game.
And the 27-year-old has responded, hitting four goals in his last three games.
Evra reckons those who wrote off Rooney made a huge mistake, saying: "People were criticising Wayne, which was normal because Robin joined and is doing great.
"But you can't forget Wayne. He scored two goals against Reading and he's scored another two goals against City.
"In the big games you need your big players and Wayne is certainly one of them."