Mills is a player that I see as limited to the predominantly run-blocking side of the offensive line. He played right tackle throughout his college career and is definitely a power player, strong like bull. He's got good footwork for a run-blocker, but the right side is where he'll make his mark. He was drafted as a tackle, but if he has to he might be able to make a shift to right guard down the line.
Mills now has the longest contract of any player that's currently capable of playing right tackle. That doesn't mean much except that he's the longest-term prospect at that particular position, but he's not without ability.
|Right Guard||Right Tackle|
|Gabe Carimi||J'Marcus Webb|
|James Brown||Gabe Carimi|
|Eben Britton||Jonathan Scott|
|Kyle Long||James Brown|
|Matt Slauson||Kyle Long|
* Again, James Brown played tackle in college, so while he played guard last year, I'll still list him as a G/T for the moment.
I think it's a pretty certain chance Mills makes the roster; there's some fair versatility in those players, but of the players listed, Long is guaranteed to stick (first round pick) and Slauson is more than likely on and starting at the other guard position. Then you add Roberto Garza and Jermon Bushrod and that's four offensive lineman locked in. Mills would make five.
From there it gets interesting. Right now, Webb is the starter at RT, but if demoted he can back up both tackle positions. Gabe Carimi was drafted as an RT but can play RT and RG - were it not for Carimi's first round money, with a strong camp Mills could make Carimi expendable, but it'll be interesting to see if a full offseason and recovery from his knee injury make Carimi a better player. If the Bears want to keep Brown without exposing him to waivers (he's still practice-squad eligible), they'd have to possibly drop Scott. Cut day should be entertaining to watch this year from an offensive line perspective.
1) Mills Backs Up Right Tackle
I know, the prospect of anybody developing behind J'Marcus Webb is scary, but there are worse fates for a player in his first year.
2) Mills Develops in Sub Package
I could see this happening quite a bit next year. Sometimes teams report a tackle as eligible in certain protections or run fronts (the Bears did it with Carimi and Brown last year, the Lions ran Riley Reiff as the sixth OL). With Mills' power and run-blocking, they could line him up wherever they need a little extra push.
3) Mills Starts at Right Tackle
I don't think Mills actually is a day one starter given the glut of veterans/experience/draft status ahead of him. But if he excites in training camp and with a couple of cuts, hey, it could happen.
Mills has some nice potential - not "All-Pro For A Decade" type potential, but enough that he might play in a second contract. A guy that can only play one side of the line doesn't have a lot of key value, but if he performs, he could make a home on a line.
Largely his future will depend on the players ahead of him. If the Bears move away from Webb and Carimi, he could find himself starting next year's opening kickoff. If Webb and Carimi straighten themselves out, then Mills finds himself expendable - which, if Webb and Carimi improved their play at right tackle, isn't that the goal all along?