The Portugal captain stripped down to just his pants for promotional shots for his CR7 range, which was officially launched a fortnight ago.
The former Ballon d'Or winner is confident that his former manager will be proud of his latest business venture.
"He's going to love them, because he loves me," Ronaldo told Shortlist.com. "This is a fantastic man – one of the most important people I've met in football.
"I have him in my heart because part of my success is because of him. He was my father in football, so I have to appreciate what he did for me."
Ronaldo left United for Madrid in 2009 after six years at Old Trafford.