What this precocious freshman didn't feel was surprise.
From the moment the nation's most coveted high school player chose the Trojans last year, he envisioned his first season on campus working out exactly this way.
"I don't feel intimidated at all," Barkley said Thursday night after another practice with the first-team offense. "There's been some great quarterbacks here, we all know that, and I'm just excited to be a part of it. ... I've been preparing this whole time like I'm the starter. That's what I came in here in January hoping to do."
Barkley will become the first non-redshirt freshman quarterback to start a season opener for the Trojans.
Coach Pete Carroll unexpectedly announced his decision two days before USC's mock game, which was expected to be a deciding factor in the derby between Barkley, Mitch Mustain and Corp, the starter out of spring practice.
Instead, Carroll and quarterbacks coach Jeremy Bates felt they didn't need to wait.
"Matt earned it," said Bates, in his first year running the Trojans' offense. "It's not based on [Corp's] injury or anything like that. Matt has made some mistakes, but he's learned from it and come back. He's made it exciting."
Barkley was almost every college recruiter's favorite passer coming out of Orange County's Mater Dei High School, the alma mater of fellow USC quarterback Matt Leinart. After choosing the Trojans, Barkley graduated one semester early to participate in USC's spring practice.
By the fifth spring workout, Carroll was shaking his head in wonder at Barkley's maturity. Carroll and Bates only worried about Barkley picking up the intricacies of the offense -- play-calling, signals and shifts -- but the freshman now has it all under control.
"It was huge to get that head start with the offense," Barkley said. "If I wasn't here in January, there's no way I'd be in this position now."
Corp, another Orange County prodigy in his third year at USC, led the competition through spring, but Barkley took advantage when Corp missed two weeks of workouts this month after developing a small crack in a bone below his left knee Aug. 10.
Corp returned to full-speed practice Tuesday while wearing a knee brace, but Carroll said he will have a limited role in Saturday's camp-ending scrimmage. Corp acknowledged he's not at full speed, though he's medically cleared to play.
"I'm more disappointed [than angry]," Corp said. "I continued to get better, and my legs are strong enough. Keep fighting, that's all I can do. I still want to play. I still expect to play. When I do get an opportunity, I'm going to make the most of it."
Barkley also beat out Mustain, the former Arkansas starter who played eight games as Mark Sanchez's backup last season. Sanchez, now the New York Jets' starting quarterback, left USC with a year of eligibility remaining, a decision that initially bothered Carroll and set off the three-way competition.
Barkley was named the Gatorade High School National Football Player of the Year for the 2007-08 season. The last five winners of this award have combined for just eight starts and 160 pass attempts in their college careers. Mustain won the award for the 2005-06 season.
Now Barkley must shoulder the enormous expectations of his position at USC. He's following a near-decade of outstanding Trojans quarterbacks, including Heisman Trophy winners Carson Palmer and Leinart, and Rose Bowl champions John David Booty and Sanchez in the past two years.
USC opens its run at an eighth consecutive Pac-10 title next weekend against the Spartans before its most daunting early test: a trip to Columbus to face No. 6 Ohio State on Sept. 12.
"I couldn't be more proud of this guy and what he's done to position himself for this," Carroll said. "Of course he's got a lot of new stuff to learn, but you couldn't do more than what he did. ... He's not a typical freshman. He hasn't acted in any way like anybody else we've had in here. Hopefully we can play well around him, and the guys are going to rally around him."
The Associated Press contributed to this story.