The tell the school to not redshirt them.Sounds like rules need to change then.... you lose too much experience when you allow them to go that early.
The NFL's rule does not take redshirting in consideration, nor should it. It's a rule for the NFL, not NCAA. And it's does because they don't want growing kids, and instead want 21 yr. old men who've stopped growing and packed on musles.
More importantly, after 3 years, a player knows if they're going to finish school or not, a decent student would only have a year left. To force them to stay there after that point is pointless.