IMO both full backs took a hard time last season due to the narrow midfield leaving them exposed. When three centre halfs played the praise the full backs got was notable. Hartleys biggest problem is being too stubborn to accept that his tactics aren't working and changing them, unless he changes his style then we are in for a tough season. Its been asked many times by fans, why don't we play to our strengths and play players in their strongest positions instead of shoe horning them into to a formation that doesn't suit???
If Hartley wants to play a specific style then he needs to get players that can play it, if they cant adapt then he needs to change his tactics.