The 24-year-old will make his first major appearance since forming part of the British men's gymnastics team that won a first Olympic medal in a century at London 2012 at the worlds in Antwerp.
A fractured tibia has limited Thomas' outings this season including missing the European Championships, which saw Britain's men win five medals in total, Max Whitlock the star performer with gold, silver and bronze.
Beijing 2008 Olympian Daniel Keatings won pommel horse gold while Sam Oldham claimed silver on the horizontal bars with all three joining Thomas on the World Championship team in addition to Dan Purvis and Ashley Watson.
These World Championships, which run from September 30 to October 6 are individual only and Thomas, while delighted to have returned to full fitness, feels an expectation to show his Olympic bronze medal-winning best.
"It was touch and go to whether I would be fit enough for the trials," said Thomas. "They tried to fast-track my training a bit and, after everything that's gone on this year, I'm just glad to be part of the team.
"It's never easy being out with injury and it was a long road back, a frustrating time. There are a lot of very good young gymnasts in the country now and there is always going to be someone who can step up and take your place.
"If they do a good job then you can quite quickly find yourself down the pecking order. I just had to concentrate on working hard on the other apparatus and it's a relief to now have the injury behind me.
"Everyone did superbly at the Europeans. It puts pressure on me when everyone does such a fantastic job. It was tough seeing them do so well and not being part of it, though of course I was pleased for them.
"As a sportsperson you are always going to suffer injuries and it's all about how you deal with them. I just tried to stay upbeat and focused on getting back to full fitness."
© Sportsbeat 2013