The midfielder completed a transfer to the French champions last summer after failing to agree a new deal with the Red Devils, whom he will face with his new side on Tuesday evening.
“It was not a secret: I was negotiating for more than one year, but I expected more from the board after my third season at the club when I was player of the year.
“They didn’t come to me that summer, they didn’t even call me. And that was very painful for me, because I had a feeling that I was giving everything.
“In saying that, I have a huge respect for Ed Woodward, a huge respect for the board. They have always treated me fantastically.
“I know they want the best for Manchester United, but in football, in life and in every company in the world sometimes you don’t think the same way, and I respect that.
“If I see Ed, I will give him a hug. We just had different opinions about Manchester United and, in my opinion, what the club should have done.
“I want to make sure everyone understands there is nothing personal at all. That’s life. But it’s true – after the third season when I was player of the year, when I had the respect and the love from the fans, I didn’t feel that love from the club.”
Since moving to Paris, Herrera has won four trophies and reached the Champions League final – where the French side were beaten 1-0 by Bayern Munich in Lisbon in August.