I had a similar problem. My freshman was the backup center and was very crucial to remaining competitive. I stripped him to the bare essentials and gave him something like 33 minutes of sh, which ended up being sufficient.
I saw the almost exact same scenerio the previous season, but ended up losing the player despite giving him about 15 minutes of sh.
Something has changed with that aspect of the game. So, if the player is important then I suggest taking the necessary precautions.