Cody Kessler

USC's Cody Kessler says he has "a new sense of confidence" now that he has been named the Trojans' starting quarterback. (Luis Sinco / Los Angeles Times / September 7, 2013)

No more looking over his shoulder.

No more worrying about making mistakes.

Instead, Cody Kessler can embrace the start of his tenure as USC's starting quarterback.

A day after Coach Lane Kiffin announced Kessler had been chosen over Max Wittek, Kessler appeared relieved and sounded excited about the opportunity to lead the Trojans, who play Boston College on Saturday at the Coliseum.

"I'm not trying to be corny," Kessler said after practice Tuesday, "but it's like he gave me the keys to the team, the keys to the car."

Kessler, a third-year sophomore from Bakersfield, started against Hawaii and Washington State but was replaced in the second half of both games by Wittek as Kiffin considered his options.

Kiffin finally made his choice after the Trojans' 10-7 loss to Washington State last Saturday.

"His words to me were, 'Let's roll, let's get it.'" Kessler said.

Kessler has completed 18 of 32 passes for 136 yards and a touchdown, with two interceptions. He's also rushed for a touchdown.

Wittek has completed eight of 18 passes for 90 yards, with one interception.

On Tuesday, Kiffin once again declined to explain why he chose Kessler over Wittek, also a third-year sophomore. But he described some of what he thought Kessler does well.

"Cody manages situations that nobody outside of our team would see," Kiffin said. "Whether that's audibles, whether that's things in the huddle, getting things fixed, getting people aligned.

"He's still, obviously, very inexperienced."

Wittek was the No. 2 quarterback and started two games in place of Matt Barkley last season. On Monday, Kiffin said he had spent "some time" with Wittek the day before to deliver the news.

"That wasn't a very extensive conversation," Wittek said Tuesday. "I mean, it was just real brief and just telling me what's going on."

Wittek acknowledged disappointment at the decision — "Just the competitive nature within me, it's just natural to feel that way" — but pledged to continue competing.

"I'm going to continue to prepare for every game," he said. "If I'm needed at any point, I'll be ready."

Kiffin has said that "ideally" freshman Max Browne would redshirt and compete for the starting job in the spring.

In the meantime, Kessler said he already felt "a new sense of confidence" that comes from "knowing that you're the guy."

Kessler had looked tentative at times in the first two games, which featured very conservative play-calling by Kiffin.