Start a new career with a new, original player
(don't use a pre-created or star player) and build up your reputation.
You can build up your reputation through responding positively after points (
) and through positive, enthusiastic press conference responses (after winning charity events, grand slams and reaching 50/100 win milestones).
There's also a photographer in the managers you can get who can boost the rate of popularity growth on the player tab. You can track your progress on the career home screen.