Good question. I could be wrong, but I seem to remember that it was not a Bills doctor.
As an aside, it seems that there is still a bit of mystery about how he originally hurt his foot.
There was no report of him injuring his foot etc. during the season, and the next thing we know, he comes back in the spring and we find out about this. I seem to recall that, initially, no one said when he hurt it. It was not until sometime later that some (Sammy) said that he originally hurt it during last season.
It could very well be that he originally hurt his foot during last season. Nevertheless, I continue to wonder whether Sammy hurt his foot during the off season.