when you do certain things in the right way. Like when a star player "test" you by asking you the ball and you pass it right away, fans react on it, they see that you're not a ball-hog. I cannot remember (Im away from my PS4 now) what else contribute to the fans positive reaction but after you reach certain level, the badges unlock. For example, because i did pass the ball right away (and another 1-2, cant remember what) now i have the Fan favorite badges.