He revealed: "My street cred can't be touched, babes! Don't worry about that. But before we started, I told the producers, 'No sequins and no Lycra'.
"At the moment, I'm not nervous, but by the time it comes to the competition I'll probably be about a nine or ten."
The former X Factor contestant said that the experience is like performing on stage with his bandmates, adding: "It's pretty similar, to be fair.
"It's a different style of dance and performance that I'm used to, but in terms of performance and learning I've definitely wanted to make sure it's right.
"It's not totally unlike being with JLS because I'm not totally on my own. You still have to be in sync, like with the boys, but it's been difficult trying to learn to not step on my partner's toes.
"Unfortunately the JLS boys can't come and watch, but they've all messaged me to say good luck."
Other celebrities competing in the show, airing on Christmas Day, include former footballer Fabrice Muamba, Blue Peter presenter Helen Skelton, comedian Katy Brand and entertainer Bobby Ball.
Gill said of his Strictly experience: "It's been great - we're just chilling with dinner, drinks, hanging out with Fabrice.
"I saw him earlier and his hips - apparently the hips don't lie. We've been winding each other up all day.
Of Rochelle Wiseman and Marvin Humes's pregnancy news, he revealed: "It's incredible. So lovely. I've seen some of the pictures and scans - I don't know what sex it is though.
"Maybe they can start their own band. They can't be in one of our bands - we'll be about 52 when they're, like 12!"
The Strictly Come Dancing Christmas Special is on BBC1 at 6.15pm on Christmas Day.
Watch Fabrice Muamba talk to Digital Spy about the Strictly Christmas special: