Peter Pannu claims Birmingham will adopt a prudent approach to avoid the financial problems which have engulfed other top-flight clubs.
Carson Yeung this week celebrates one year in charge at St Andrew's, during which time he has rebuilt the playing staff, adding the likes of Alexander Hleb, Ben Foster and Nikola Zigic to the payroll.
But City vice-chairman Pannu has warned fans not to expect the spending to continue unchecked.
"Carson wants to build the club but he is also equally mindful of the pitfalls of improving at a pace that could cause problems for the club," Pannu told the Birmingham Mail.
"It has to be done at a more sustainable level, step by step.
"The fans wish to see improvements on the pitch but how you achieve that is important.
"Blindly demanding the owners pump in money to secure established players is equivalent to a wife saying 'if you don't do this and that on credit, then I will leave you'.
"I think none of our fans would do that but will try to satisfy the wife in a different way or call it quits.
"In the context of a financial household situation, running a football club is no different."
Despite his cautious words, Pannu insists Yeung will continue backing Blues manager Alex McLeish.
"If people want to run clubs completely on a benefactors model, they will end up in the situation that Portsmouth were in, that many clubs were in - and will be in," he continued.
"I'm not saying Carson is going to turn off the taps but we can see many clubs are beginning to be financially prudent on spending.
"That might be bad news for players but good news for the industry."