The CheckerBoard

Ok, I follow a lot of football, but I've never played the game (obviously) so I have a question about defensive scheme. Doug Matthews was quoted as saying that he thinks we should shift to a zone- read I the secondary, instead of man-to-man, which obviously isn't working for us so far this year. So here are my questions:

1) how difficult is it to make that switch from a man-to-man to a zone read? Is it something that could have been done in the off-week?
2) have you heard any hints that would lead you to believe that the Vols made that switch in the off-week? Obviously the coaches are not going to announce a scheme change to the world, just wondered if you had heard anything hat might cause you to think the had made that type of schematic change.