To play with a great team on career mode, first choose your favorite team on the beginning screen. Then, go to the player creation screen. Create the players that you want or need. At the team options screen, send them to your team, then go to career mode. In the screen that appears before the game (squad and formation screen), make the necessary substitutions. This is an easy way to play on professional or world class level, and give your players all the needed stats.