If you crash out of the cups early doors, or have nothing to play for in the league, then just play tons of friendlies every day, making sure you have ticket prices sorted so you earn revenue and you will soon see money start to grow. If you are tanking the season then it doesn't matter how fit your players are, as long as you can field a team - in that case as you need money I would simply play friendlies all day, pushing the bank balance up.