Herrera broke his silence on Wednesday over the transfer saga which saw United's late bid to sign the 24-year-old before the transfer window closed end in failure and a degree of farce on Monday night.
United saw an initial offer for Herrera rejected by Athletic last week with the Basque club's president Josu Urrutia insisting they would not negotiate for their players and that if the Red Devils wanted their man they would have to pay the release clause in his contract of around £30.75million.
David Moyes' side were still being linked with Herrera right up until the close of the transfer window but no move was forthcoming.
Speaking at a press conference on Wednesday, Herrera insisted he had not had talks with United, but admitted the English side might have struggled to turn his head anyway.
He said: "Obviously when United make an offer for you it's very flattering and I'm very grateful, but I'm very happy with Athletic.
"I didn't pass a medical as has been said. Athletic have made things clear in an honest way from the start.
"In the first place the club have to pay the clause, which is 36 million euros for me, and then attract me more than Athletic do, which is very difficult.
"It's totally false that an agreement was reached with me. To talk with me they would've had to pay the clause."
Asked if he felt let down at all by United, Herrera said: "Not at all. How am I going to feel mistreated when a club of the level of United make a formal offer?"