USC football: Aundrey Walker pushing Max Tuerk at left tackle

USC left tackle Aundrey Walker is expected to be challenged by Max Tuerk this weekend with Lane Kiffin's announcement that both will play against Colorado, according to Michael Lev of the Orange County Register.

#USC coach Lane Kiffin said he expects both Aundrey Walker and Max Tuerk to play at LT vs. Colorado. Starter TBD

— Michael Lev (@LevOnUSC) October 17, 2012

This is the second time Walker's job security has been challenged this season with the last coming after Stanford's upset victory over the Trojans.

Walker, a massive 6'6, 300-pound sophomore, has had an up-and-down campaign with this being his first season covering Matt Barkley's blindside. Beyond the obvious technique issues, Walker has had trouble with false starts and leads the team in penalties, according to Kiffin.

Tuerk, a true freshman, has the frame of a prototypical left tackle at 6'6 but he's yet to truly fill out clocking in at around 270-pounds. Still, the talent is there as an ESPNHS.com All-American first teamer last year so it shouldn't be long before Tuerk permanently leap frogs Walker on the depth chart if the struggles keep up.

Despite all the hullabaloo, the Trojans really haven't had a hard time keeping Barkley upright this season. They're currently only allowing 1.67 sacks per game despite Barkley dropping back for an average of 32.2 pass attempts each week.