The Spain midfielder has made 126 appearances for the Red Devils since his 2014 move from Athletic Bilbao and has become a fan favourite.
Herrera was voted the Sir Matt Busby Player of the Year at Old Trafford last season, an accolade voted for by the United supporters.
However, the 28-year-old has found himself down the pecking order since the summer arrival of Nemanja Matic, making just one Premier League start for the club so far this season.
"I feel as important as I did last season," Herrera told the Manchester Evening News. "I am a team player and I always say that and if the manager decides to keep me on the bench I will be ready.
"I said that last season and it is the same now. I know how lucky I am to play for Manchester United. I will try to enjoy every minute I have on the pitch. I want to win titles and feel part of the team and feel important and I really do feel important because the manager makes me feel important.
"I am happy to be part of Manchester United. When you play for the biggest club it is not so easy to play ever game, every minute. This is a team and when I retire I want to be remembered in this club. I will never regret my time here."
Herrera is believed to be on the radar of Spanish giants Barcelona.