The practice squad is a possibility, much more than the regular roster, IMO. That said, if he can play, how long do you think it'll be until some other team signs him? Not long.
This is much like the Kennard Cox pick last year. They simply don't have room on the roster and regardless of the quality of the player, that makes it a very questionable pick. Whether its Harris, Youboty or Corner, someone probably has to go once the final cut downs occur. Granted, its just a 6th rounder, but it makes one wonder what the front office is thinking.