player problem v important

i bought a five star player and after a while, the stars are gone... only one star left... how can i solve this?:mad::mad:

How many season that player is in your team? Every season when you advance in the next league level, your players are going to lose one star. Their quality stays the same, just stars are scaled down. But if you don't train your player he will stagnate and that's not a good thing