Most of the people reacting on this thread understood where I was coming from, but let's put it another way for the others: I know I cannot use the boosters I don't have, which is why I took my potential case of a defeat.

When you go on a minus balance on your T11 bank account, you have 7 days to put it back to a positive balance. And you normally cannot go on a negative money balance by just making this decision, it's a combination of factors (players wages, you won all the auctions at the same time, etc...) which will force you to solve your negative balance within 7 days before being forced to sell your best player(s).

So, by wondering whether the morale boosters could go on negative due to a combination of factors, I was also wondering what would be the "punishment" if I don't solve the situation after x amount of days.

Problem solved now thanks to the help of some kind persons. Many thanks to them !

Cheers.