Debug Mode 
Press R3 when at the "home" screen. A debug mode will appear.

Swap for money
Start the game with 2 human players pick any team you want for yourself.Than 
pick Real Madrid. Go to find player club when your are with you team go to real 
madrid pick ronaldo and then compare with your worst player...than swap the two 
players do that as many times as you like for every time youll get 10 million 
dollars if you did that a thousand times put ronaldo back at real and go to 
manager options for real madrid and quit carreer.