"Rooney is carrying the United team this season. We must pay great attention to him," the Frenchman said. "He's having a tremendous season and I am happy for him. He's a player I like a lot.
"He's hungry. He gives everything for his team. He will tackle, he defends, he attacks, he scores goals. He's full of confidence."
Ribery added that while he understands why United have been named as the overwhelming favourites to go through to the final four of the competition, he has urged his team mates to believe they can cause an upset.
"The whole world sees us as losing," he added. "But I think we have a great chance. We have a team good enough to believe in."