From experience, I know providers like Fantrax and CBS provide deep benches / farm team spots where you can place players that are currently not on your active roter. It's a lot to enter at first but it works.
I'm sure guys like Shakedown or Dyzfunctioned around these boards could jump in and give more details on how to set it up.
Assistant Manager - DobberSports.com
Writer - Fantrax.com
Regular Guest - The York Report via NextSportStar.com