The Spaniard came famously close to joining Real Madrid back in 2015 but the move fell through amid a series of documentation issues.
Since then, speculation of a move to the Spanish capital has emerged but the 26-year-old has remained calm over his future following a successful year under Jose Mourinho.
And Herrera, when asked about his teammate, made it clear that he would go nowhere as long as Man United kept fighting for trophies and remained in the Champions League.
“I can see him staying here for more years, but we need to win titles to keep him with us,” he said. “That is what we did last season.”
“David is really happy at the moment because we are fighting for everything. We won three titles last season, and the FA Cup the year before, and that is what he wants.
“Real Madrid are going to talk about it every summer because he is the best keeper in the world. But we don’t think we are far from Real Madrid — we won three titles last season, the only English team to do it. We are going to enjoy having him here and try to keep him at the club for as long as possible. If he is not a legend already, he is not too far away from being one of the legends of the club.
“For me, he is the No. 1. I respect all the keepers like Manuel Neuer, Gianluigi Buffon and Marc-Andre ter Stegen, but David right now is the No. 1 in the world.
“He is very calm, and that is the thing that always surprises me the most about him. He has that quality. It comes from God. He makes a difference. It makes a difference when you have a keeper who wins you points. He is one of the few keepers who can give you points. I think he is in that position now where he intimidates strikers.
“He has been in the club six years and the first six months he told me were difficult for him, but after that he has been the best. Every single season he has been the best and you know how difficult it is for a keeper in the Premier League because even sometimes the referees don’t give you some fouls.
“He makes some unbelievable saves. Even in training we end up laughing at times, because we try to score and it is just impossible.”
The sheer brilliance of De Gea hasn’t received the same limelight over the last year as other players have grabbed the headlines, but make no mistake: there aren’t many more important players in this side than the Spaniard.
United’s late surge against Everton on Sunday, which took them joint top of the table, was only made possible by the 26-year-old’s reliability between the sticks. He quashed the momentum generated by the visitors in the second half by making close range saves from Wayne Rooney and Gylfi Siggurdson – still the last player to score past him at Old Trafford all the way back in April – before producing a superb diving stop from Sandro Ramirez.
This was yet another episode of De Gea quietly saving the day and laying the platform for others to write headlines.