You can’t solve one problem and at the same time create another, because you won’t be able to do anything good for the team, but will only make the situation worse. Perhaps by selling De Jong you will be able to cover some of the debts, but at the same time the team will have a problematic position in which they will not have a good performer and this will lead to the fact that the final results for the season will be worse if the player remained in his position. So the problem needs to be solved with an integrated approach, for example, not trying to sell someone from the team, but limiting new transfers and trying to achieve better results.
Even though it can't cover some of the debt, at least Barcelona doesn't have to pay player salaries that are too high.
If Barcelona wants to solve the club's financial problems they must try to stabilize player salaries and if possible sell some of the players who have large salaries.
The effect of this option will be to make Barcelona problematic in facing competition for the title because they do not have quality and experienced players.
Another way is not to recruit new players and try to find sponsors who can cover the financial burden required. This would be much better because they would not have to sell quality players for huge salaries.
I think Barcelona must find a solution because if not this will continue to drag on and could affect the team's performance.