To unlock this trophy, you have to play against every team in a Season.
Once you load into the game and are in the lobby, press on the "Play" button, navigate towards "CUSTOM GAMES" and press it. Choose "SEASON" and press "START NEW SEASON". I would recommend putting the settings like this:
Team Size: Doesn't matter if you're going for this trophy
Difficulty: Doesn't matter if you're going for this trophy
Season Length: Doesn't matter if you're going for this trophy
Playoffs Teams: Doesn't matter if you're going for this trophy
You can choose any type of settings it will automatically be given after the ninth match of a Season, so don't worry.
Press "CONTINUE" to move on. The rounds will take 5 minutes long so if you do 5 * 9 it will only take around 45 minutes.
After 9 matches of the season, you will unlock: Team Player