Despite picking up some pleasing results in the cup competitions, United have endured a tough start to the Barclays Premier League title defence with back-to-back defeats at Manchester City and at home against West Brom.
Rafael says Wednesday's hard-fought 1-1 draw against Shakhtar Donetsk has boosted the squad ahead of Saturday's trip to struggling Sunderland, with a victory the Reds' only focus.
"The cup competitions have gone well for us, we have done well there. But we are all focused on the next game because we need to win again in the league," the Brazilian told ManUtd.com.
"Results like Wednesday's help you. It was a good result for us. We started well and scored, and they didn't have many chances to score, maybe only one or two. We defended well apart from their goal.
"Everyone has confidence in each other and trusts each other. I see that every day in training," he added. "The spirit is fantastic. We just need to stay focused in every game and make sure we get the results now."