The U.S. actor was approached last year (13) to host a British panel show but he was unaware of the term and assumed he was being offered a judging role on a high-profile singing competition.
However, he was left stunned when producers of the new programme landed him a spot on Celebrity Juice as an introduction to the format - and he was confronted with fellow guests telling lewd anecdotes and saucy, foul-mouthed jokes.
MCHale tells British Tv show This Morning, "They called me (and said), 'Do you want to do a panel show?' and I was, like, 'What is that? No.' To me it's like, oh is that sitting behind a panel and judging, like on The X Factor or something? I was like, sure, I can criticise people.
"I happened to be here (in the U.K.) last summer and I met up with some of them and they told me their ideas and they were so nice and funny and hilarious I was like, 'I will do whatever you guys want me to do.' They put me on Celebrity Juice so I could see it and I think that was a great introduction to the panel world!"
MCHale's new show, Virtually Famous, pits two teams against each other to score points with their knowledge of online viral content and social media news. It is due to air in the U.K. from next week (beg28Jul14).