In MyCareer, you have a cap on how high your core stats (three-point shooting, agility, etc.) can be at any given time. To increase this cap, you need to fill up a meter that can only be filled by doing practice mini-games in your daily schedule.
Unfortunately, the practice drills are tedious at best and downright broken at worst. Short one-on-one matchups, shooting drills and wind-sprints are probably an integral part of a normal basketball practice, but they don't make for especially engaging gameplay.
What's downright inexcusable, though, is whenever the game makes you run drills involving setting screens or using the pick and roll. It makes absolutely zero effort to explain what these things mean or how they should be used for more casual players, and more often than not, the game's controls simply stop working during these drills.
Case in point: I had a screen drill that required me to run to a spot on the court and press the circle button on my PS4 controller. Easy enough, right? Well, the circle button didn't do anything. I stood there, smashing the circle button in the vain hope that something might actually happen until the 90-second timer ran out and I failed the drill.
Things like that have happened to me multiple times. I guess it's possible that I'm missing something (but how could I with something so simple?), but I'm going to assume it's just broken.