The 20-year-old was issued with a straight red card for a two-footed challenge on Jonny Evans in the first half, with the England international clashing with Ferguson on his way off the pitch.
Shelvey revealed he went up the Red Devils boss after the 2-1 defeat to apologise for his actions but the midfielder still insisted he has no regrets over the tackle.
“If I had pulled out of a tackle against Manchester United, I would probably have hurt myself and the fans would have gone mental,” Shelvey told Liverpool’s website.
“That walk [from the field] felt like a mile but I had seen Alex Ferguson in the fourth official’s ear so I said to him: ‘It’s your fault I got sent off’.
“After the game I had just picked up my friend and his girlfriend from the players’ lounge and I was walking back down the tunnel towards the car park and saw him coming towards me.
“I pulled him and apologised for what I had done. I said it was wrong and I was frustrated. I’m a young boy and emotions got the better of me but I said I still wouldn’t have pulled out of that tackle.
“He said it took a man to apologise. He said it is an emotional game and not to worry about it.
“My dad has always brought me up to respect people but, if you have opinions and if you are in the right, don’t be afraid to say so.”
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