Richardson played with Keane at Manchester United and linked up with him at Sunderland when the Irishman was manager.
The 29-year-old winger joined Villa from Fulham last week and is looking forward to once more teaming up with Keane, who was recently appointed as Paul Lambert's assistant and helped Richardson through one of the toughest moments of his career.
"That season when I signed for Sunderland I think I only played 10 games because I had a hairline fracture in the L5 vertebrae in my spine," Richardson told Villa's official website.
"Throughout that season I was very upset, I put on a lot of weight and I got bigger.
"But just before the end of that season, Roy took me into his office and we had a massive conversation.
"He inspired me to go away in the summer and come back in better shape than I had ever been in.
"I went and played very well in the next season.
"He gave me some good words of encouragement to go and do that over the summer and I appreciate that."
