Go to "Office", and if a player is close to reaching his peak, sell him. Do not sell him to a rival team or you may not be able to get him back. You can view his status under "Team Management", then select "Player Growth". Buy that player again at the next transfer season after his peak has been reached. Buying him again will increase his overall rating. Note: This can only be done once. To have him grow faster, go to "Office", then "Calendar". Schedule training sessions so players can grow. Do not give them too much training or it will affect their fatigue.