Van Gaal named Rooney as the United skipper on Tuesday and he will wear the armband as permanent captain for the first time in Saturday's Premier League opener against Swansea at Old Trafford.
Before handing him the armband, United manager van Gaal reminded Rooney he must be a role model for United players and fans both on the pitch and off it.
His indiscipline has cost him in the past, but Rooney says he is now up to the task of being a responsible and successful captain.
"It's a massive role to take on, I'm aware of that, the responsibility of it. I feel I'm ready at this stage in my career to do it," Rooney told United Uncovered.
"I spoke to the manager and he decided that I was right to take the role which I am delighted with. It's a great honour. I will perform the role as best I can and hopefully help the team to be successful."
Rooney has been stand-in captain on several occasions during his 10-year spell at United, but this is the first time he has been given the honour on a full-time basis.
However, he can draw from the experience of playing under the captaincy of inspirational leaders like Roy Keane, John Terry and Steven Gerrard for both United and England.
"I've played under some great captains for club and country so I will take a little bit of what they have brought to the role and try to use that," Rooney added.
"Then I'll try to lead the players on the pitch with hard work, dedication, and that's what we really want to do -- we want to show the fans that we care and want to win."
Robin van Persie, van Gaal's captain with the Netherlands, was regarded as the initial front-runner for the armband at United.
But van Gaal is adamant van Persie won't have a problem with either the decision or Rooney, with whom the Dutch striker is said to have a sometimes difficult relationship.
"It was not difficult," Van Gaal said when asked if it was hard to overlook Van Persie. "I didn't say it to him. He was not there at that moment. I told it personally to Wayne, then I had to choose the vice-captain, then I had to say it to my players. This is a different situation to the Dutch national team.
"I think you always have to choose a native captain. I don't think there's any problem."