His stamina has to be a concern. I've seen his tape, not just his highlights. I've also seen him raise his hand to come out after 3 plays in a series. Carter has only played 390 snaps in each of his last two seasons. By comparison, Jeffery Simmons has averaged 870 snaps per season over the last 3. The reason why Carter only averages 6 tackles for a loss and 2 sacks per season is because he's playing less than 50% of the defensive snaps. He has to improve his stamina to improve his chances of becoming an all-pro. Unfortunately, the reports on him are that he doesn't give 100% effort in practice or the weight room. The conjecture is that he may not have the drive to become great and has been getting by on his physical attributes only. The big red flag for me was coming in overweight for his pro day and not being able to finish his workout. Quite honestly, I can't remember another top draft pick bombing their workout so poorly. If anyone can provide another example, I would love to know.