After opening 2014 with successive defeats against Tottenham, Swansea and Sunderland, David Moyes' men are on the brink of a fourth straight loss for the first time since October 1961.
Swansea again provide the opposition at Old Trafford.
And whilst Rooney misses out after being sent for some warm weather training in a bid to shrug off a groin problem, he wants United's supporters to keep the faith.
"The crowd can help the team's confidence massively so hopefully everyone will get behind the lads and stay with them and the manager throughout the game," he said on his Facebook page.
Moyes insists Rooney's injury is not serious and the England forward could return for next weekend's showdown with Chelsea at Stamford Bridge.
But with Robin van Persie's return from a thigh injury still unknown, it leaves United relying on Danny Welbeck and Javier Hernandez to find some extended scoring form.
So far, it has proved elusive, with so many familiar faces performing below expectations.
Not that Moyes feels there is any evidence to support the belief of some critics that a number of title winners are happy to hide in the shadows and let their manager take the flak.
"I don't think any of the Manchester United players are," he said.
"Every one of them is standing up and doing what they can.
"You can never ask anyone to do more than their best and the players here are doing that."
Sir Alex Ferguson will almost certainly be present, as he was at Sunderland on Tuesday, when he sat alongside Sir Bobby Charlton and former skipper Bryan Robson and watched another sorry performance unfold.
Ferguson has been a regular presence at United matches since recovering from his summer hip operation.
It has led to questions about his involvement, with some critics wondering why the 72-year-old cannot distance himself from life at Old Trafford and get on with his retirement, as he intended.
Yet Moyes is adamant he has no issue with the situation.
"It tells you that people don't know me and don't know Sir Alex," Moyes told MUTV.
"People are saying it because they have no idea about how it works.
"Sir Alex has been fantastic. He has been incredibly supportive and is only there to help me.
"I have a conversation with him when I need it and I tend to see him for a minute or two after the games.
"I have found him great and it has been the same with Sir Bobby and Bryan Robson."
I still blame his agent for his transfer requests. he is very badly managed.- bob the manc