Detroit Lions training camp just began a couple days ago, so it's still far too early to make any concrete conclusions about certain sections of the 53-man roster and the depth chart. Some spots are indeed already set, but for the spots that are up for grabs, we need a lot more than two practices to make any final determinations.
With all that said, it is interesting to see what kind of rotations the Lions are using right now at certain positions. On the offensive line, for example, it's notable that Corey Hilliard and LaAdrian Waddle are both getting first-team reps at right tackle. That's an indication that there is a real battle going on at that position, and it's an indication that the Lions' starting offensive line currently looks like this:
LT Riley Reiff | LG Rob Sims | C Dominic Raiola | RG Larry Warford | RT Hilliard/Waddle
There's far more uncertainty with the second-team offensive line simply because basically all of the spots are up for grabs right now. What's more, the backups are getting work at multiple positions, so the second-team offensive line could change on a daily basis. Keep that in mind as you take a look at the second-team O-line from earlier this week (via Mike Mady):
LT Michael Williams | LG Rodney Austin | C Darren Keyton | RG Travis Swanson | RT Hilliard/Waddle
This is merely one snapshot of the second-team offensive line, but it is interesting that Williams worked as the No. 2 left tackle earlier this week. That doesn't necessarily mean he's ahead of Cornelius Lucas considering the depth chart (or rep chart, as Jim Caldwell likes to call it) is still a work in progress, but if nothing else, Williams seems to have made decent progress since switching from tight end to offensive tackle a couple months ago.
For the interior of the offensive line, the rotation isn't quite as interesting simply because all three players are likely getting work at all three positions. Versatility is important at offensive guard and center, and Austin and Swanson especially need to be able to play multiple positions considering they are expected to make the 53-man roster as backups.