Let's operate under the assumption that at one time, JT Turner had the physique of a shut-down corner.
Based on practice reports and observations, JT Turner experienced a bit of a growth spurt, and as a result, is having difficulty covering receivers. If he added bad weight (fat), it is easy to rectify the situation. However, it sounds as though he has also added some muscle, which at the cornerback position, is not necessarily a good thing.
So now the question becomes, do the coaches move him to a different position or keep him at corner? Based on our current depth at the position and his potential, it's probably best to keep him there.
Do you think the coaches have encouraged him to decrease muscle mass? Should they? Has this been done successfully with any players in the past?