The Bournemouth player moved to St Andrew's on a temporary basis at the end of January and has made seven appearances, including two goals in the win over Derby County.
Thomas wants to continue to impress for Birmingham and could do so in front of potential new employers when Lee Clark's side visit Crystal Palace on Friday.
"If you can put in a good performance, you might catch someone's eye," he told Sky Sports News.
Thomas added: "You are playing for your future. That is one of the things I keep in the back of my mind. You have to work hard and keep on grafting.
"If I do not, I could find myself without a Championship club."