USC moves into the second week of training camp Monday still searching for answers on several fronts, none as important as left tackle.
Coach Lane Kiffin installed sophomore Aundrey Walker as quarterback Matt Barkley's blind-side protector during spring practice, but the 6-foot-6, 300-pound sophomore was sidelined again Sunday because of injuries.
With less than three weeks before the Sept. 1 opener against Hawaii, redshirt sophomore Nathan Guertler, a 6-5, 270-pound walk-on from Norco, has taken most of the first-team reps in Walker's place.
Max Tuerk, a freshman who played at Santa Margarita High, also took snaps at left tackle Saturday and Sunday.
"He's doing great," Kiffin said of the 6-6, 285-pound Tuerk. "Obviously, that's a long, long ways to go there, but I think he's going to be a really good player wherever he ends up."
Junior Kevin Graf, who started at right tackle last season, played on the left side for a few days during spring practice before Kiffin gave Walker the job. Asked Sunday whether the 6-6, 300-pound Graf was in competition on the left side, Kiffin said "probably not."
"To double switch and to move him back over there," Kiffin said, "probably doesn't make a whole lot of sense right now."
The defensive line also remains a work in progress and it might have suffered a blow Sunday when redshirt freshman end Greg Townsend Jr. went down with an apparent ankle injury.
Linebacker depth also could be an issue. Middle linebacker Lamar Dawson was sidelined for the last few days, so Hayes Pullard moved to the middle and redshirt freshman Anthony Sarao played on the weak side. The Trojans were already thin at the spot after Tre Madden was switched to tailback, and Madden suffered a season-ending knee injury in spring practice.
Meantime, De'Von Flournoy has shown that experience counts. The fourth-year junior continues to build on his impressive spring and assert himself as the probable No. 3 receiver.
Josh Shaw, a transfer from Florida, has been one of the top newcomers. The 6-1, 190-pound Shaw came in as a safety but is playing with the first unit at cornerback opposite Nickell Robey.
"I'll do whatever they want me to as long as I can help the team and get on the field," Shaw said.
Kiffin said the Trojans would spend the second week of practice attempting "to get really good at the little things" and to play well on offense, defense and special teams before they begin preparing for specific opponents.
A goal-line drill on Sunday featured the usual mid-August mix of athleticism, ego, fatigue, a heat index in the 90s and ear-piercing music thumping from speakers just outside the end zone.
Tempers, of course, flared during the drill, allowing coaches to chastise players while not-so-secretly reveling in the scene.
Safety T.J. McDonald clearly enjoyed the moment, saying he sensed frustration from offensive stars such as Barkley and receivers Robert Woods and Marqise Lee.
"That's good for them," McDonald said. "They need to be frustrated."
Cornerback Torin Harris did not practice because of an undisclosed injury, but Kiffin said he expected Harris to return soon…. The Trojans were scheduled to have their second double-day workout Monday, but the morning session was canceled.