Vidic is pleased with the form he has shown this season since being handed the armband by manager Sir Alex Ferguson.
He said: "Obviously there's a bit more responsibility and I'm coming to the age when I have more responsibility, me and a few others in the team.
"I am quite happy with that and I'm enjoying it.
"It's not a question you should ask me, about my performances and how I play this season. I'm at an age now where I have to take more responsibility as a player.
"When I came here I was 24 and I was still young and a lot of older players took responsibility on the pitch.
"But now I have to do that, be supportive to the younger players and be an example. It's something that comes naturally as you get older.
"The more responsibility you have and the more pressure you have, I think the better your focus and concentration are. So it helps."