FIFA 20 faced a huge backlash from players when its career mode simply wasn't up to scratch -- especially at launch. The mode was pretty much busted in more ways than one, but EA Sports seems eager to make up for past mistakes with FIFA 21's offering.
The overarching theme here is that everything is designed to be more in-depth. Match simulations are now much more interactive, allowing you to manage player energy levels and tactics through a new simulation menu. Player development is also a big talking point, as you'll apparently be given more control over the growth of your squad. It also sounds like player stats will improve more noticeably if they're working hard in training, and playing against tougher opposition.
You can even change a player's position, transforming a defender into a midfielder, or a winger into a striker, for example. You won't be able to turn Virgil van Dijk into a world class forward overnight since more drastic transformations will require a lot more training, but this sounds like a nice addition.
Speaking of training, you can now create schedules and better manage your entire team when it comes to off the pitch activities. Honestly, this all sounds promising, but we'll have to see whether everything comes together as planned when FIFA 21 launches in October.