D'Brickashaw Ferguson sat out the morning practice, but it wasn't due to any kind of injury.
Ferguson was the top performer in the team's off-season conditioning program, and the reward was getting to sit out of practice during training camp. And this morning he took advantage of this.
Ferguson needed to get bigger and stronger, and he clearly did that. Now he truly looks like he's his listed size of 6-6, 312.
David Harris on the other hand is clearly hobbling with some kind of leg injury, perhaps a hamstring injury, and that is why he sat out.