The Red Devils attempted to sign the 24-year-old during the summer transfer window, but they were unable to convince Bilbao to part with their midfielder.
However, rather than be disappointed that a move to the Premier League champions fell through, Herrera has claimed that Bilbao is the "perfect place" for him.
""I appreciate very much that Manchester United made a very important offer for me and also that Athletic did not accept it," he told Canal+. "That means that Athletic value me above money and trust in their project more than a large offer.
"I'm where I wanted to be in this day, not someone who has played for six or seven clubs. I like to feel good where I am, take root and Athletic is the perfect place for me."
Herrera has made 10 appearances for his Basque employers this term.