Fall camp preview: Offensive line

If you've read any of my season previews and predictions before, it should be pretty clear that I'm a sucker for returning starters. Returning starters seems like a pretty simple measure when compared to other stats, but that's because it is.
I love digging in to advanced stats as much as any other nerd, but you can't quantify what a returning starter brings to the football team. The experience and stability they bring to the table is invaluable, especially on the offensive line. A team with linemen that are comfortable next to each other has a big advantage over one that has to start from scratch in the trenches.
Returning a lot of starts on the offensive line isn't a guarantee of success, but I sure like to see it when I'm making my predictions. The Badgers return three linemen from last season who combined for 44 career starts, but they still have a few questions to answer when fall camp starts on Aug. 5.
Can they prevent a repeat of last year's struggles?
The Badgers expected that their offensive line would continue to perform at a high level under new coach Mike Markuson, but they couldn't have been more wrong. Markuson and his players clashed over the techniques and style Markuson wanted to implement, and Bret Bielema eventually canned him just two weeks into the season. Bart Miller helped the offensive line regain some traction as the interim head coach, but the Badgers can't afford to fall flat right out of the gate again this year.
To his credit, new offensive line coach T.J. Woods seems to have fit right in with the players and the scheme they want to run. There were rumblings about Markuson's transition dating back to spring camp, but everyone seemed to be on the same page this year. That's important for a unit that still needs to find two new starters, but we'll have to wait and see if Woods can get the Badgers back to being one of the top offensive lines in the country.
Who will start at center and left guard?
Ryan Groy, Kyle Costigan, and Rob Havenstein will all return to their starting roles this season, although Groy is making the switch from left guard to left tackle. But at the end of spring the Badgers still needed to identify two new starters on the interior of the offensive line.
However, I can't see anyone beating out Dan Voltz at center. Voltz redshirted last season as Travis Frederick's understudy, and he's been on campus for three semesters already, even though he'll just be a redshirt freshman this season. Voltz had some snap issues when he first arrived on campus, but it looked like he's cleaned those up for the most part. The Badgers will still probably see a drop off from Frederick, who started 31 games during his career, but Voltz should be ready to go when the Badgers open their regular season.
The competition is a little murkier at left guard. Zac Matthias and Dallas Lewallen look like the top two contenders at the moment, but both players have struggled with injuries during their careers. Matthias has more experience (four career starts), but I think Lewallen is the better fit on the left side. At 6-foot-6 and 318 pounds Lewallen has great size for the position, and he got a lot of reps at left guard during the spring. This is still an open competition; so keep an eye on these two players when practices start up again.
Is there enough depth to get them through the season?
Gary Andersen and Woods were both a little unnerved by how thin the Badgers were on the offensive line during the spring. Costigan and Havenstein both sat out for much of the spring so that they wouldn't aggravate previous injuries, and the Badgers made sure not to overwork Groy as well. That gave younger players like Ray Ball and Tyler Marz an opportunity to work with the first team, but the Badgers just don't have a lot of experienced depth behind their starters. If one of them were to get injured, the Badgers would likely be hurting to replace them.
However, they do have a bunch of incoming freshmen this fall. That should help their depth issues down the road, but the coaching staff will have to keep working the recruiting trail to make sure they get up to the 15 or so offensive linemen that Andersen feels most comfortable with. And Andersen would probably sleep better at night if someone like Jack Keeler or Matt Miller were to step on to campus and show they could contribute sooner rather than later.