If his shoulder is not right now (as was the problem before) it is most likely due to continued symptoms of recovery related to the fusion, or another level of unaddressed disc bulging is symptomatic. With 1 level fusion, few orthopods totally recommend nixing return to contact sports, but will tend to encourage about 1 year. With 2-3 levels most will feel uncomfortable, and with 4 no way.
No matter what, running upright puts an RB at great risk for snapping of the neck. And certainly running backwards as he likes to do (an which he did in this game) leaves him open to that dreaded whiplash injury which can easily result in additional disc problems. If the grafted segment holds, there is that much more torque load that the other segments are exposed to, thus cervical disc injury. Keep remembering that Slaton's shoulder and hand problems were always caused by nerve compression related to his disc problem. He was never noted to have an independent shoulder pathology.
Last year, he most likely ran upright because with a cervical disc, extension of the neck reproduces/exaccerbates the nerve compression symptoms of the disc problem (positive Spurling test). If you run low, you have to extend your neck to see where you are going .
In essentially all of his hits Saturday night, his necked snapped back (in hyperextension). I'm surprised that he has not been fitted with a Cowboy collar, which has been proven in studies to significantly limit cervical hyperextension.
