LOS ANGELES -- USC coach Lane Kiffin told ESPNLosAngeles.com on Wednesday that he thinks there is a "huge under-appreciation" by Trojans fans for how quarterback Matt Barkley played in his four seasons at the school.

He also predicted big things for Barkley in the NFL despite the QB's recent slide in some mock drafts.

Barkley surprised many in December 2011 by electing to return for his senior season. Then, he was widely viewed as a top-10 prospect, but he has fallen out of the first round on most mock draft boards. Neither of ESPN's draft experts, Mel Kiper Jr. or Todd McShay, projects Barkley to go in the first round.

Barkley will throw for scouts late next month at USC's pro day.

"I think he's going to be a great starting quarterback in the NFL, and the film shows it," Kiffin said. "The plays he makes, all the throws he's made here, the leadership qualities ... I've said this before: If Matt Barkley had the defense that Matt Leinart and Carson Palmer had, Matt Barkley would have won the Heisman Trophy just like they did. He would have had the winning records they had."

Barkley's stock likely was hurt by USC's disappointing 7-6 season after a preseason No. 1 ranking, by his 15 interceptions (up from seven in 2011) and by the shoulder injury that ended his season two games early.

Barkley took some heat from USC fans as the Trojans' offense regressed slightly from a 10-2 season in 2011. The Trojans gained an average of 12 yards fewer per game and scored roughly a field goal less per game. It was largely defensive breakdowns that caused USC's downfall. The architect of the Trojans' defense, Monte Kiffin, resigned after the season and now is defensive coordinator of the Dallas Cowboys. USC hired former Cal defensive coordinator Clancy Pendergast to install a 5-2 scheme it hopes will be more effective against spread offenses.