Vidic believes United are capable of going from strength to strength this season.
"We won the Premier League last season, but I can still hear people asking 'are we good enough?' People are still questioning this team," the United captain told The Sun.
"It seems like we have to prove something again. Well, it is up to us to do that. We have nothing against that, we just have to work hard and show that we are good enough.
"I am looking forward to this season and I think we will be better than last season."
For the big stories and the banter follow us on Twitter: @tribalfootball