Logan has been mingling backstage at Eurovision for the past week.
But although he agreed to an interview with Today FM's Ray D'Arcy, who has flown to Dusseldorf to broadcast, he was not on Mooney's show.
"We met Johnny Logan on Wednesday and were hoping he'd come on the show but apparently he didn't want to because he thought we were going to stitch him up," explained Derek.
"I don't understand what that was about because we try never to get involved in anything that's going on but not to worry.
"It was interesting when he walked into the media centre to see how they descended on him, he is real Eurovision royalty."
Asked if he thought Johnny's concerns were sparked by the fact that the RTE show has been championing Jedward, he added: "I honestly don't know. I don't want Johnny Logan to think I would be having a go at him because I'm not like that, it's not my style."
It's understood that Logan has been at loggerheads with the station ever since his controversial comments about Jedward and the fact that he's not their biggest fan.
"I never said that Jedward were an embarrassment to Ireland," Logan said.
"What I said was that I find them embarrassing to watch. It's like watching two Frank Spencers in Some Mother's Do 'Ave 'Em. It's like watching a train crash -- you can't look away, but at the same time you don't want to see it."
Meanwhile, Louis Walsh hit out again at Logan.
"Why is Johnny being so negative about these kids?" he said. "All he has to do is go see -- they're getting an amazing reaction."
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