"We have to be better this season. If we play at the same standard as last season, we will not be good enough to win the league."
Vidic is excited at the quality of United's close-season signings, with Nani impressing in their pre-season games.
"Nani looks great," the defender said. "He's sharp and strong, he has a lot of stamina and he will be an important player for our team."