Injuries cost you real money.

[gogs67]

You don't 'need' to heal your players, you don't 'need' to win all the time.
Deliberately tank every second or third season and just let the injuries happen and don't spend the money.
I've been playing for 16 seasons, won the league last year, looks like I may win again this season and here's what I've got just by not using them in seasons I don't need to