As compared to the previous version of the game Mut 23 Coins, Madden 23 allows you to upgrade your player via Training. Simply press X/Square when selecting the player card and choose Upgrade. This way you'll train your player for an upgrade. Higher level cards such as the Gold and Elite can only be upgraded once. However, there are some cards that can be upgraded more than that. Cards such as the Power Up-type player cards. These cards allow you to upgrade more than once using Training.
The method in itself is very simple. First, what you need to do is to quickly sell every single card that you do not need. Sell your Gold Cards and your Silver Cards for as high as you possibly can. Use some of your lower Silver Cards in your playbooks and then sell the playbooks for as much cash as you can.
Continue your flash sale for as long as possible. Eventually, you will have around 50.000 coins. This is where you can start having fun. What you need to do is to use your hard-earned money to get the Pierre Garcon Flashbacks card. This Wide Receiver Card has a rating of 87.
Although the card itself is one of the most terrible ones that you can get for the same amount of price, it has a hidden use that you can exploit to essentially make your team perform much better than it would. By now, you will be aware of where this is going.
Once you have the Pierre Garcon flashback card Cheap Madden 23 Coins, you can sell it for 775 Training Points. This is by far the highest amount of Training Points you can get for around 50.000 coins. Once you have this, you can use the points to upgrade whatever it is that you wanted to upgrade.