The Red Devils captain will make his comeback today against Sunderland at Old Trafford after playing just five games over the last 12 months due to a knee injury.
Many doubt whether the powerful centre-half, 31, will still have the ability and aura of his past.
But Vidic said: "I have worked hard to be the same player again and I have the determination not to drop the quality of my game.
"There will be pressure. When you play for United you don't have time for people to wait for you.
"When I got the first injury I was out for six months and people were saying 'Is he going to be the same? 'Can he play for United?'
"This is the challenge you have to deal with.
"But when you have been out for the best part of a year - after having always played - I think I will need to go through a few games to get my form back but I'm confident that I can deal with that.
"Obviously, it's a challenge for me when I come back, firstly to be in the same form as I was but also to help the team.
"As someone who has had six years here and, at 31, with some good years still left to play, I feel a responsibility."