Chris Galippo made his first start of the season count in USC's 48-14 victory over California on Saturday.
The junior from Corona, who was supplanted at middle linebacker by sophomore Devon Kennard, started at the weak-side spot in place of injured Malcolm Smith and made six tackles.
Galippo has played on the strong side and also in a rush-end position, but he did not begin playing on the weak side until Monday.
"In five days he had to learn a whole new position," said Monte Kiffin, USC's assistant head coach for defense.
Galippo, who committed a crucial penalty in last week's loss at Stanford, tied Kennard with a team-best six tackles against Cal.
"It's a little bit different playing out in open space," Galippo said. "But I think our defense as a whole is really jelling and learning to play off each other's emotions, and that's one more step of maturity."
Barkley stays hot
Just as he did in the season opener against Hawaii, USC quarterback Matt Barkley passed for five touchdowns, tying the school's single-game record.
Coach Lane Kiffin gave Barkley three opportunities to get the record on his final series in the third quarter, but two passes fell incomplete and another was caught out of the end zone.
Barkley has not had a pass intercepted since Sept. 25, when he had two picked off against Washington State. He has passed for 20 touchdowns with four interceptions.
"I was pretty mad about the last red-zone opportunity we missed, but points-wise and effort-wise, we played our most complete game," Barkley said. "And that's what we needed."
Gable injures knee
Senior tailback C.J. Gable, who had his most productive game of the season, suffered a knee injury when he was tackled on a fourth-quarter kickoff return.
The severity of the injury was unclear, Lane Kiffin initially saying it might be season-ending, but Gable later emerged from the locker room on crutches and said doctors had not determined the extent of the damage.
"I'm not going to let it bring me down," said Gable, who rushed for 72 yards and had 52 yards in kick returns. "I'm going to come back stronger."
Houston comes through
Kicker Joe Houston, who entered the game having made two of six field-goal attempts, kicked two 27-yarders against Cal.
"I'm just happy for my teammates — top to bottom we played a good game and it just felt good to contribute," Houston said. "I'm confident — I have to be. My team counts on me. Even in a high-scoring game, I still have to come through, so it feels good. I finally had a good game."
Houston also lined up for an apparent 52-yard attempt in the first quarter, but he pooch-punted to Cal's eight-yard line.
McDonald, Harris intercept passes
Safety T.J. McDonald and defensive lineman DaJohn Harris set up second-quarter touchdowns with interceptions.
McDonald, a sophomore, has a team-best three interceptions.
Harris, a fourth-year junior who also played tight end at Gardena Serra High, returned his interception nine yards.
''The ball was coming to me in slow motion," he said. "I was like, 'No way!' I had not caught a ball since high school.''