Ronaldo left Untied for Real Madrid in a world record £80million deal over the summer.
“I don’t want to play against Manchester,” he said.
“It will be a strange feeling if I play them. Mr (Sir Alex) Ferguson helped me a lot in my career. I was there six years and he taught me many things.
“I keep the same relationship with him. He’s a good friend of mine. I still have the same friends. I speak sometimes with (Wayne) Rooney, (Nemanja) Vidic, (Rio) Ferdinand, Nani, (Patrice) Evra, Anderson.”