Despite the talent, they inexplicably came into each season looking like 5 turnstiles. They got much better during each season, but 2 years in a row of being as bad as they were early (especially given the talent) is a huge concern.
Losing Josh Lugg will (hopefully) help (love the kid and he's a great rep for ND) because that guy still makes too many mistakes that let free runners into the backfield for a very experienced olineman.