I don't think it's Diggs injured. It's Allen.
My argument:
1. Major uptick in Cook usage and rb stable.
2. Lack of deep ball frequency.
3. Still trying to get ball to your best playmaker (Diggs) but seemingly more passes at line of scrimmage. (not deep).
4. Allen accuracy has dropped.
5. Increase in short pass game.
Something is up, and my money is on Allen is dealing with something and the play calling is being worked around that.