The Red Devils dropped out of the top four last weekend after slumping to their second straight Premier League defeat at home to Norwich City.
Losses to Bournemouth and the Canaries compounded United’s Champions League exit at the hands of Wolfsburg earlier in the month.
United travel to the Britannia Stadium on Boxing Day looking to return to winning ways before hosting Chelsea at Old Trafford on Monday 28 December.
And Rooney has told his team-mates that they must go back to basics against the Potters as they look to start the hectic festive schedule by picking up three points.
Rooney told MUTV: “I think confidence is obviously low and that is understandable because we have had some bad results, but we need to pick it up.
“We have some important games coming up now, we need to stick together and fight our way through this. We need to try to get maximum points in the next two games because it could be a defining moment in the season.
“We obviously need to go into the game with more confidence and with the attitude that we know we are going to win the game. Sometimes that is doing the simple things right, which can help you a lot, so we have had a good week of training and hopefully we can take some of the sessions into the game, perform well and get the three points against Stoke.
“Through all of the preparation, we have known – as well as the manager – how important this game is. We all have to stick together and we can’t look too far ahead of the next few days. We have two big games coming up [Stoke and Chelsea] and we need to prepare and be ready for them both.”
United, who have not won the title since Sir Alex Ferguson’s retirement in 2013, finished fourth last season in Louis van Gaal’s first campaign in charge at the club.
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