Robbie Williams rejected Queen's offer to become late frontman Freddie Mercury's replacement because he didn't feel worthy enough.
The former Take That star has revealed Brian May and Roger Taylor invited him to step into the music legend's shoes after he laid down the vocals on a re-recorded version of their hit 'We Are The Champions' for the soundtrack to 'A Knight's Tale' in 2001.
However, the 'Rock DJ' hitmaker explained that he has "very low self-esteem" and would've found it "too scary" taking Freddie's place, because he was so "godlike".
In an interview with SiriusXM, Robbie said: "Even though I'm very confident here on the microphone, I have very low self-esteem.
"And I just thought I'd save them the audacity of me even trying to step on a stage and be the same echelon as Freddie Mercury.
"He, to me, is angelic. He's godlike. It was just too scary."
The 46-year-old pop star also admitted that he wasn't keen on the idea of having to split his earnings with the rest of the band.
He said: "I was doing stadiums myself at the time. I didn't want to have to split it three ways, but that's another story."
And whilst he didn't have the "audacity" to replace Freddie - who died in 1991 aged 45 due to complications from AIDS - Robbie says Adam Lambert, who has been performing as their frontman since 2014, is the perfect person for the job.
The 'I Love My Life' singer even quipped that the 'American Idol' alumni gives him a "talent hard-on".
He said: "Adam Lambert - if he wasn't such a lovely person, which he is - I would just be terrified of him because of his pure talent.
"His voice is absolutely incredible.
"And he's an incredible performer, and a lovely person to boot. "I'm really pleased when I meet people that I'm just overawed by their talent - he gives me a talent hard-on - and they're nice.
"It's much better than meeting people that give you a talent hard-on and they're assholes. You're just like, 'Oh, I hate everything you've done now.'"