With injuries decimating the roster and a quarterback competition keeping the spring interesting, it was defense, not offense, that characterized this Saturday’s third football practice of the spring season.

Frontrunner · Sophomore Matt Barkley remains ahead of senior Mitch Mustain in USC coach Lane Kiffin’s quarterback competition. - Carlo Acenas | Daily Trojan

The practice, the Trojans’ first in full pads, gave the team its first real taste of full contact practice, which caused some injuries to freshman running back Dillon Baxter and fourth-year safety Marshall Jones.

“It was a very physical, very long practice, but guys need to learn to get hurt and continue to play,” USC coach Lane Kiffin said.

Despite the injuries, the defensive unit took full advantage of practice to show its strength.

Senior cornerback Shareece Wright, who will be the most experienced member of the USC secondary, made his presence known during the team’s scrimmage by intercepting senior quarterback Mitch Mustain’s pass.

“I felt the route coming and just broke on the ball,” Wright said of his interception.

Wright’s performance on the practice field Saturday helped him continue to grow into his role as a defensive leader.

“I try my best to work with the younger guys and show leadership on the team,” Wright said. “It’s leading by example more than anything.”

Wright was not the only defender to take advantage of a mistake on Saturday.

One of Wright’s backfield-mates, junior cornerback T.J. Bryant, intercepted sophomore quarterback Matt Barkley’s pass into coverage in the endzone — giving both competitors for the starting quarterback role interceptions on the day.

“We had a couple of turnovers and I’m excited about that,” USC secondary coach Willie Mack Garza said. “Any time we can intercept the football and get it back for the offense and in position to score points, that’s a great play. We need to get more of them.”

Asked after practice which quarterback had the edge on the competition, Kiffin gave the slight edge to Barkley, but assured the media that the two competitors would continue to split reps in practice as they had last week.

“It’s real early, we’ll let both guys alternate in [the offense] and see where it goes,” Kiffin said.

Barkley, who started all but one of the Trojans games last season, continued to impress Kiffin with his handling of the scrimmage offense in the first three practices of the season.

“[The competition] is based on accuracy and handling of the offense — getting to your second and third reads,” Kiffin said.