The 19-year-old England goalkeeper is being chased by several teams, most notably Liverpool, who are understood to have already been in talks with the midlands outfit.
Blues rejected a £6million bid from Southampton for Butland in the summer, but acting chairman Peter Pannu has admitted the cash-strapped club may not be able to resist such temptations next month as they bid to ease their increasing financial struggles.
"I can't say that we are in a very wonderful situation, I would be lying if I said that," Pannu told the Birmingham Mail
"This is a very tricky question (player sales). What I can say is that - and I might be blasted for this by the fans - but no-one is for sale and everyone is available. As at any club.
"Give me a £15m offer for Jack Butland, can I say no?
"I have rejected £6m from Southampton (in the summer) but I rejected it when our finances were okay.
"As the time is ticking, I might not be able to reject it if I get something similar.
"I do have a responsibility to keep the club running.
"My top priority now - and if I do offend anyone, I care not - is to make sure this clubs stays afloat."
- Sports & Recreation