United suffered only their second loss in 16 Barclays Premier League games on Saturday when Swansea completed their first-ever double over the Old Trafford side with a 2-1 win at the Liberty Stadium.
The defeat raised fears United could miss out on Champions League qualification for a second successive season and their gloom deepened as striker Robin van Persie left south Wales on crutches and with a protective boot on his injured right foot
Van Persie will have the injury assessed by the club's medical staff amid fears that he could be sidelined for a few weeks - but United skipper Rooney has called for an instant response at home to Sunderland next weekend.
"We need to hit back next week," Rooney told MUTV.
"There are still a lot of games to go and we have to bounce back from this quickly, go on another good run and try to keep us in a good position to finish in that top four."
United had lost only once since the derby defeat to Manchester City in early-November, at home to fellow Champions League chasers Southampton in January.
But there has been growing supporters' disquiet over performances and manager Louis Van Gaal's tactics and Swansea repeated their opening-day victory at Old Trafford in August by wiping out Ander Herrera's 28th minute strike.
Ki Sung-yueng equalised within two minutes and Bafetimbi Gomis was credited with the 73rd minute winner when he inadvertently deflected Jonjo Shelvey's powerful strike past stranded United goalkeeper David de Gea.
Van Gaal said he was "amazed" by defeat after United had enjoyed greater possession and territory and Rooney agreed with that sentiment even though the visitors managed only three shots on goal during the entire afternoon.
"Of course, it is hard to take," Rooney said
"Certainly, in the second half, I thought we dominated up until they scored and I thought we got a great goal to go 1-0 up.
"In the second half they were struggling to get out but then they hit us with a sucker punch, a shot from 30 yards and a deflected goal.
"But maybe we didn't test the keeper enough up until they scored, that's disappointing given the play we had.
"It was one-way traffic and it felt like that on the pitch, it felt like a matter of time.
"It is a blow for us, coming away with no points having played like that."
Swansea had not beaten United at home since January 1982 when Alan Curtis and Robbie James scored in a 2-0 Vetch Field victory in the old first division.
But goalkeeper Lukasz Fabianski felt Swansea's tactics were spot-on as Garry Monk's men managed only a second win in eight league attempts.
"We might not have had complete control of the game, but we made sure they didn't have many chances," Fabianski said.
"I think at Old Trafford we had more possession and looked more comfortable on the ball.
"United had more possession here but they didn't create that much and nothing clear-cut.
"It's a massive achievement for Swansea and I think we can be really proud of the performance."
Swansea's victory took them to 37 points and with 12 games to go they are on course to beat their best Premier League total of 47 points.
"We have to try to get as many points as we can in the last 12 games and see where it takes us," Fabianski said.
"It would be a great achievement to make this Swansea's best season in the Premier League.
"It will give us extra motivation to keep pushing."
Source : PA
Source: PA