Thomas moved to St Andrew's from Bournemouth on transfer deadline day, on a loan agreement which is due to run until the summer.
He opened his goal account for Birmingham in a 3-1 victory over Derby County on Saturday, and is looking to kick on from this point.
The former Queens Park Rangers trainee feels he is capable of competing at Championship level and would welcome the opportunity to prove that under Lee Clark.
"This is a big club, without a doubt the biggest one I have played for," Thomas said in the Birmingham Mail.
"I'd be buzzing if the manager came to me at the end of the season and said he wanted to sign me.
"But it's up to me, I have got to keep on scoring goals and keep on working hard."
The 26-year-old striker added: "I think I'm at the age where if I don't take this opportunity, I might not get another one.
"I have to work hard in every training session, do well in every game, to try and get a contract and prove as a player that I can do it at this level."