Help! Players having major difficulties possessing the puck!

Try going to Settings > Gameplay Sliders to see if there's a reset button there. If not, let me know which console you're on and I'll give you some instructions for manually deleting it. However, that also deletes your offline game saves so if this is happening in Franchise Mode or Be A Pro, it's very possible those saves will be lost. They normally download from the cloud, but I can't guarantee that.