The Spain Under-21 international kept a clean sheet at Craven Cottage and pulled off some stunning saves to once again prove his quality. Despite evidence to the contrary, the media continue to cast doubt over the youngster's grip on the goalkeeper's position at the club.
However, Rooney was joined by Jonny Evans and Sir Alex Ferguson in praising the former Atletico Madrid man for his display in West London after his last trip to the capital ended with harsh criticism for his part in the build-up to Clint Dempsey's late equaliser for Tottenham.
"He was superb," stated Rooney. "I think he's been great for us over the last few weeks as he's made some great saves.
"I know he got a little bit of criticism after the Tottenham game but he made five or six world-class saves in that game and it wasn't the biggest mistake I've ever seen.
"We're all behind him and backing him. He's a great player for us and for the future as well."
Commanding centre-back Evans claims he was not surprised to see De Gea pull off a magnificent fingertip save to divert a Bryan Ruiz shot against the woodwork.
"He made some outstanding saves, especially the one from Ruiz, which he tipped onto the post," explained Evans. "We’re used to seeing that from him. We didn’t necessarily think, ‘great save’, because we’re used to him doing that. I think people underestimate his shot-stopping ability."