It was announced yesterday that the winger would be returning to his native Australia at the end of the Super League season.
The Wigan coach told Sky Sports News: "He told me a couple of weeks ago that he was going and I really admire him. He's a good man who has done a lot of things that people don't know about behind the scenes at this club, things in team meetings and things like that.
"He's an outstanding individual. I wanted to give him a new deal, I don't want him to go. But his kids are at an age where they are ready to start school and his mind was made up. I have kids, I know what it's like, so I understand it. Paddy has loved it here but he wants to go."
Two late penalties from Richards helped the Warriors secure a 28-20 win over Hull FC last night.