The 32-year-old singer - who shot to fame after appearing on 'American Idol' in 2009 - now tours with Queen, and the band's original drummer says the flamboyant star reminds him of the 'Jailhouse Rock' hitmaking icon when on stage.
He joked: ''My nickname for him is Camp Elvis.
''His presence and charisma reminds me of Presley in so many ways, the look, the showmanship, the overtly sexual attitude.''
Although the 65-year-old musician noted Adam's resemblance to Elvis, he also admitted he thinks the singer is extremely similar to original Queen frontman Freddie Mercury, who died of an AIDS-related illness at the age of 45 in 1991.
He continued: ''He is absolutely scintillating on stage, a voice in a million, and the same was true of Freddie. There are almost frightening similarities, especially socially, as an overtly gay man full of wit and banter.''
Although Adam insists he has not ''replaced'' Freddie in the band - which is why they are billed as ''Queen + Adam Lambert'' when they tour together - Roger revealed he feels much closer to the late singer when he is performing with the singer-songwriter because of their similarities.
He said: ''There are some moments backstage when it seems like nothing has changed at all.''
Despite the faith Roger and guitarist Brian May place in the rising star, the 'If I Had You' hitmaker said he still finds it difficult performing for ''die-hard'' fans of the band.
Adam told the Sunday Telegraph newspaper: ''I had a little bit of trouble with 'Don't Stop Me Now'.
''The guys would say, 'Hey, it's OK, you don't have to do it just like the record. Freddie used to modulate down and find ways to make parts easier for himself'.
''But Freddie was allowed to do what he wanted because it was his song. I have a different standard that I'm up against. I have to do the big note or they're gonna say I can't cut it.''
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