The I’m A Celebrity alum revealed he was diagnosed with the chronic illness, which causes pain, swelling and stiffness in the joints, earlier this year.
Despite his excitement about attempting Latin and ballroom routines, the 35-year-old explained that he doesn’t know if he’ll be physically able to attempt any of the dances dazzling lifts.
He told The Standard: “We’ll see. I’m going to try my hardest, but look, it is going to set me back a little bit. I’m just going to try my best.”
“I’ve been through physio with the guys, they know what I can and cannot do,” Thomas added about how his diagnosis might impact his performances on the series.
“I’m just going to have to take it easy, and hopefully it’ll hold up. But right now, I’m in no pain. So it’s all positive.”
Last month, Thomas spoke about his rheumatoid arthritis diagnosis for the first time as he confirmed his Strictly stint, which he said he signed up to “be able to move again”.
He wrote at the time: “As much as I act like a kid, my body is telling another story. I’ve been in a lot of pain since January, it started with my knees and then travelled to my wrists, fingers and now ankles and toes.
“I never knew what was happening and finally after several blood tests and back and forth to doctors and hospitals, I’ve been diagnosed with rheumatoid arthritis! I thought that was something people, later on in [their] life get… but that’s not the case, clearly!
“Some days are better than others and I’m not going to lie, it’s been hard not being able to train properly. It has had a huge knock on effect for me personally, but not only that for my family too!” he contined.
“The reason I signed up to Strictly is because I just want to be able to move again, get fit and do it, all with a smile on my face! It really couldn’t have come at a better time.
“I’m a firm believer of everything happening for a reason, and I know the journey I’ve been on was meant to happen, to never take small things in life for granted! Like going for a run, playing with my kids and just being able to walk with no pain!
“I know it’s going to be tough and I’ve definitely got my work cut out but I am up for the challenge and cannot wait to get on that dance floor!”
Thomas will be joined on the series by fellow soap stars ex-Coronation Street actress Ellie Leach as well as EastEnders actors both past and present, Bobby Brazier and Nigel Harman.
The Strictly line-up also includes Paralympic champion Jody Cundy and former British number one tennis player Annabel Croft as well as BBC Asian Network’s Breakfast Show host Nikita Kanda.
Actress Amanda Abbington, Bad Education star Layton Williams and broadcaster Angela Rippon also join the mix along with news broadcaster Krishnan Guru-Murthy, comedian Eddie Kadi, Les Dennis, Irish TV presenter Angela Scanlon and Zara McDermott, the first Love Island signing for the show.
Presenters Tess Daly and Claudia Winkleman will also be back in hosting duties alongside judges Shirley Ballas, Craig Revel Horwood, Motsi Mabuse, and Anton Du Beke.
Strictly Come Dancing returns Saturday, September 16 at 6.35pm on BBC One and BBC iPlayer