Simon Cowell "wasn't sure" if hiring Rita Ora and Nick Grimshaw for 'The X Factor' was the right decision.

Simon Cowell

Simon Cowell

The 55-year-old music mogul has admitted he initially had second thoughts after sacking long-time judge Louis Walsh in favour of the 'Poison' hitmaker and BBC Radio 1 DJ.

He said: "I wasn't sure. Normally whenever we have anyone new in I'm on the phone to Louis within three hours to replace them. I'm sure he had his bags packed at the front door."

However, Simon is now happy with his decision and is thrilled with Rita despite describing her as a "ditz".

He told The Sun newspaper: "She's a bit of a ditz, but it's part of her personality. What I like about her is that she's not afraid to admit that.

"She doesn't say something and then scream at the producers to edit it out. She can poke fun at herself."

The 'Britain's Got Talent' judge - who has two adorable dogs named Squiddly and Diddly - also claimed new judge Nick has a pet-like quality.

Simon added: "People have always said to me that [Nick's] like everyone's best friend and I didn't work it out until I met him. He's like a really friendly dog, really friendly, he always wants to be stroked and be happy."

Meanwhile, Cheryl Fernandez-Versini will also be returning as a judge when the ITV signing competition kicks off its 11th series.