Academy director Terry Westley is expected to be in charge of team affairs for Saturday's home clash with Portsmouth if Black leaves Birmingham.
But a source close to the club told PA Sport: "What manager in his right mind is going to want to come to Birmingham as things currently stand?
"He might join on Monday and then be sacked next month if Carson Yeung somehow manages to raise the funds needed to buy Birmingham.
"It is a nightmare situation for the club, who only six months ago were euphoric after gaining promotion back to the Premier League. Now it all looks to be falling apart."