Posted by ESPN.com's Adam Rittenberg

Wisconsin's quarterback conundrum has created plenty of angst in Mad-town, but the Badgers have always been able to hang their hats on a formidable run game and a reliable offensive line.

It turns out Wisconsin's line depth will be put to the test early on this season.

Starting center John Moffitt (pectoral muscle) and starting right guard Bill Nagy (heel) have yet to to return to practice and could miss Saturday's opener against Northern Illinois. Starting left tackle Gabe Carimi, who injured his knee at a practice I attended Aug. 18, has returned to practice and should start against the Huskies.

Moffitt told me he was close to a return and did some individual drills at the practice I attended, though he hasn't made it back for full contact.

"[Moffitt and Nagy] may return this week," head coach Bret Bielema told reporters Monday. "If not, we expect to have them back next week. It is kind of day-by-day with those guys. They have put themselves in a position as good as they can. It's just a matter of how well their body responds to what they’re doing. They're both in full gear and doing certain things with the trainers.

"They just haven't gone live against our defense."

Wisconsin is certainly getting a lot younger this year, though offensive line appeared to be one of the team's more seasoned units. If Moffitt and Nagy can't go Saturday, freshman Travis Frederick and sophomore Kevin Zeitler likely would start in their places at center and left guard, respectively.