If you're new to the mode, players have worked out a way to offload huge numbers of players by making use of the "Unassigned" pile.
While these unassigned cards would usually prevent you from opening fresh packs, a workaround from FIFA 20 may just work in FIFA 21.
FIFA 21 Ultimate Team: How To Open Packs With Unassigned Items
This sneaky trick could help you make a tonne of coins
Unfortunately, it's just not possible to open packs with unassigned items.
Instead, players will either need to store in their club, Quick Sell the items, or stick them on their transfer list.
That said, there is a way you can amass plenty of Unassigned players...
The Unassigned Glitch
Now, there's a good chance that this loophole could be closed with FIFA 21, but for the time being, here's a handy explainer from FIFA YouTuber TheSpicyTurtle.
As the video shows, you'll want to pick up the players you're planning to sell on either by bidding or by hitting their "Buy Now" price.
Once done, head to the Transfer Targets menu and press LT or L2 to "Assign All".
When asked about keeping players, press B or Circle and select "Exit and Sort Items Later".
The list will be limited to 50 players in your "Claim New Items Tab", but rest assured, they're all there! It's a handy way to then sell a wealth of players at once, but remember - investing in the wrong players can be a risky business!