The only way I’ve found to improve your players during the off-season is to do exhibition games. I find the only time my players improve is after a game (of any kind). Practices help stats as well but I’m thinking they happen around the same time as the game plays but not sure. Practices don’t seem to happen during the off-season. So make sure to schedule your 3 exhibition games, one of which after your recruiting is done so you can get your incoming freshman a little boost.