On one hand, I know we haven't seen so much as a preseason snap from Mo Harris.
On the other hand, I'm wracking my brain for examples of veteran receivers who joined the Patriots and seemed to instantly click into the offense and find rapport with Brady in TC, who then amounted to nothing. Or, come to think of it, examples of vet WRs who seemed to flail helplessly when learning the offense in camp, but who totally locked in later. When it comes to vets and this system, early signs are pretty predictive.
I'm calling Harris a lock.