Manchester United manager Jose Mourinho has admitted he didn't treat Bastian Schweinsteiger "right" before the playmaker joined Chicago Fire.
Schweinsteiger joined MLS club Chicago Fire after a difficult season under Mourinho in which he was initially exiled from first-team training.
While granting an interview to New York Times earlier in the week, the 32 year old former Germany international described the time as a "character test" and that his "dream came true" when he was able to battle his way back into contention and play again at Old Trafford.
Speaking about the midfielder's departure at his news conference on Friday, Mourinho said: "He's in the category of players that I feel sorry for something that I did to him.
"I don't want to speak about him as a player, I don't want to speak as I buy or not to buy. I want to speak about him as a professional, as a human being.
"The last thing I told him before he left: 'I was not right with you once, I have to be right with you now.' So when he was asking me to let him leave I had to say 'yes, you can leave' because I did it once, I cannot do it twice.
"So I feel sorry for the first period with him, he knows that. I am happy that he knows because I told him.
I will miss a good guy, a good professional, a good influence in training - a very good influence.
"I could not stop him to go even knowing that until the end of the season we have so many matches and we would probably need him for a few matches or a few periods.
"I had to let him go and now publicly wish him and his wife a very happy life in Chicago."
Asked if he regrets the way he treated him, Mourinho said: "Yeah, I do."
The self styled "special one" recently said that he would never have approved some of the signings made before his arrival, but the manager would not be drawn on whether Schweinsteiger was one of those.
Mourinho is of the opinion that he was left with what he considered to be a bloated squad, but admitted Schweinsteiger deserve to be in his team
"I would let him be in the squad," he said. "I knew that at that moment we had too many players.
"If you remember at that time, we had many players in these doubtful situations and we still had [Morgan] Schneiderlin and [Memphis] Depay, and we had Andreas Pereira, Tyler Blackett and James Wilson.
"We had a huge squad in the beginning but -- after knowing him as a professional, as a person, the way he was behaving and respecting my decisions as a manager -- yes, I regret, and no problem for me to admit it and he knows that because I told him."