That's the risk I wouldn't want to take. Sometimes it's better to take a step down and consider your chances in a longer run. Every time you have to spend interests, it's a waste of money. If you're not 100% to promote, it's time to rebuild - even though it would hurt right now.
Just take a look at my team. I'm making money but won't promote as pahkitsa
(172888) has a team no-one is able to beat if he has money to waste 700k weekly. He's got to have had an enormous bankroll prior his surge for an ultimate team.