But the highly-rated midfielder admits that he was flattered by the interest from the Premier League champions.
Herrera reportedly came close to joining United on transfer deadline day.
"The only option, as the president said, was to pay my clause. I was never told United would pay the clause," he said.
"At no time have either I or my agent reached an agreement with United.
"I've been silent because the important thing was (Sunday's) game at Real Madrid. Today I'm here, with no problem, with the truth.
"I will continue to demonstrate my commitment to the club as I have since the first day I arrived. I speak for me. I do not speak of other cases. The club can confirm that my behaviour has been fantastic.
"I'm very flattered to see that one of the biggest clubs in the world, such as United, bid for me (but) I did not talk at any time with United. I've been very quiet."