"When I found out he was going to become a father I was gobsmacked. I never thought there would be room in Simon's life for anyone except the person he loves most in the world - himself", Piers revealed.
Speaking to the Daily Mail, Piers added: "I'm sure he and Eric enjoy many cuddles and he's a great dad. I'm very happy for him. I never expected to see him settled down with a baby though"
Piers Morgan was shocked at his friend Simon Cowell's news
Simon and partner Lauren Silverman welcomed their firstborn baby Eric on Valentine's Day this year. Simon had to skip some of Britain's Got Talent auditions when he travelled to New York for the birth.
Simon now has to juggle fatherhood with his return to hit ITV show The X Factor, along with Louis Walsh, pop star Cheryl Fernandez-Versini, and former Spice Girl Mel B.
"I watched X Factor recently and I like having Cheryl back," Piers also revealed.
"It's great with her and Mel B and Simon seems to have gotten his mojo back. He probably would have had to grovel. And he treated her so terribly in America that she deserves it."
Piers Morgan and Simon Cowell at the races in 2014
Despite being besotted with his little bundle of joy – who he regularly posts photos of on Twitter, including Eric enjoying bath time - Simon admitted that he hasn't embraced all of the hands-on activities.
"I still haven't changed a nappy," he said. "I don't think you have to. You don't have to. You have a choice."
Fellow judge Cheryl, who married her French beau Jean-Bernard in a secret ceremony in July, added: "I haven't changed Eric's nappy yet, but I'd be more inclined than Simon."