See this
previous thread and look particularly at the 8th post.
Bylaw 14.5.5.2.10.1 may perhaps be a way to play without sitting, provided the player wasn't recruited at the D3. You'd definitely want to contact the NCAA if the player is thinking of transferring, because demonstrating that the player wasn't recruited at the D3 may be difficult. Also, it isn't clear that the NCAA really intended for this particular (obscure) bylaw to apply to baseball once the transfer exception was removed.