Scholes, who retired at the end of last season and has been awarded a testimonial next week against Eric Cantona's New York Cosmos, played for United his entire career but believes he was lucky to do so after refusing to join a shadow side for the clash against Arsenal.
Sir Alex Ferguson has ended United careers for less but let Scholes off with a fine.
"I don't know why I did what I did in 2001, but it is something I really regretted doing," the former England midfielder is quoted as saying in several national newspapers.
"I wasn't in a great mood. I had been left out the Liverpool game the previous weekend and I knew that the team going down to Arsenal in the cup was basically a reserve side.
"I just got a bee in my bonnet that I wasn't happy with things. I had my reasons but it was stupid really. I ended up getting fined and having to apologise, but I was lucky. The manager would have been within his rights to get rid of me."