Seeing as Madden Mobile uses cards to represent NFL players, it was probably just a matter of time before EA got around to using the time-honored method of having some cards make others more powerful. To get started with training, you can either tap the ‘Train Players’ button from the home screen or the smaller button of the same name within the ‘Edit Lineup’ screen under ‘My Team (https://www.onlinegameshop.com).’
At the bottom of the screen are the players you can use to train the player, as well as the amount of training points they will supply. If you have any training items — found as either rewards for specific Live Events or in certain kinds of card packs — they will show up here as well. The important thing to remember for either cards or items is that once you use them for training, they’re gone for good.