I don't buy that we need to play Martell to keep him from transferring. Dwayne Haskins could be gone next year, and then Martell is the most senior guy left. There's also the fact that he's one Dwayne Haskins injury away from being the starter.
Now, should we play Martell because he has some unique skills that would be useful in certain situations? Sure. But I don't think we need to play him to keep him happy--he seems a smart kid who's not going to hop ship the second things get a little tough for him.