With the 2013 season just seven months away—I know, it's never going to get here fast enough—it's never too early to start counting your losses before the spring game picks you right up again, right?
We've gone through each Pac-12 team's core units* and noted the losses in each unit. Some teams have a few holes here and there while others aren't so lucky. We then went ahead and ranked each team from the lowest to highest returning core starters.
In other words, if you return enough guys in each unit to not have to rebuild—rather, reload—you're looking pretty good.
*Some schools' depth charts were not official, so keep in mind that these evaluations are based on the best information we have at the time.