Palmer, the Heisman Trophy winner, and All-American safety Troy Polamalu are two of nine starters who must be replaced from a team that restored USC to national prominence by finishing 11-2 under second-year Coach Pete Carroll.
"We have a lot of changes we have to endure with the loss of Carson and Troy and some of the other seniors, but we're really excited about the future," Carroll said after the Trojans had beaten Iowa, 38-17, at Miami. "These guys have set such a tremendous standard for us in the way that we work and the way we styled our program. It feels like we're just starting. I'm hoping we can keep this thing moving ahead."
Trojan players -- along with USC administrators and fans -- hope Carroll will resist the overtures he is almost certain to attract from NFL teams. Carroll, who coached the New England Patriots and New York Jets before he replaced Paul Hackett at USC, said during the bowl week that he preferred the total control and fun he enjoyed in the college setting to the seriousness of the NFL.
Replacing Palmer, who passed for 3,942 yards and 33 touchdowns this season, is the most serious challenge facing the Trojans.
Carroll and offensive coordinator Norm Chow monitored the possible replacements throughout training camp and during bowl preparations. Redshirt sophomore Matt Cassel, redshirt freshmen Matt Leinart and Billy Hart, and sophomore Brandon Hance, who transferred to USC from Purdue, shared increased repetitions, and competition will heat up during spring practice.
After Thursday night's victory, quarterback coach Steve Sarkisian was asked when he would begin planning for spring.
"Tomorrow," Sarkisian said. "We'll start focusing on what we've got and figure out how we're going to handle it."
Cassel was Palmer's main backup this season, but he threw only four passes, completing three for 27 yards. Neither Leinart nor Hart threw a pass. Hance redshirted while recovering from shoulder surgery.
"I'm looking forward to it," Hart said. "Hopefully, we'll all get a shot to win the job."
Freshman Hershel Dennis is expected to replace seniors Justin Fargas and Sultan McCullough at tailback. Dennis rushed for 190 yards in 47 carries this season.
Freshman Brandon Hancock and sophomore Lee Webb will compete to succeed Malaefou MacKenzie at fullback.
Redshirt juniors D. Hale and Jason Mitchell and redshirt freshman Chris McFoy are among a group hoping to step in for wide receiver Kareem Kelly, who combined with freshman Mike Williams and junior Keary Colbert to give USC one of the nation's most formidable receiving trios.
Freshmen Fred Matua and Kyle Williams will be part of an offensive line that loses only one starter, right guard Zach Wilson. Junior Eric Torres, who started at four positions this season, suffered a broken ankle against Iowa but should be back for training camp.
"We're going to have an experienced group and be even better next year," said tackle Winston Justice, a freshman All-American this season.
The defensive line will return almost intact and will be regarded as perhaps the best in the nation.
Sophomore defensive tackle Shaun Cody probably was on his way to postseason honors before he tore a knee ligament against California on Oct. 12. Cody is recovering from surgery and will reclaim the position that senior Bernard Riley filled down the stretch. Junior end Omar Nazel, sophomore end Kenechi Udeze and sophomore nose tackle Mike Patterson are other returning starters.
"We can't slack off," Patterson said. "We've got to hit the weight room and conditioning in the summer so we can come back and do another good job."
Junior cornerback Marcell Allmond is the only returning starter in the secondary, but experienced players will compete for spots vacated by Polamalu, cornerback Darrell Rideaux and free safety DeShaun Hill.
"We're going to be just as strong," Allmond said. "Everyone is going to have to fight for a position."
Redshirt sophomore Jason Leach started in place of Polamalu at strong safety against Iowa and led the Trojans with four interceptions this season. Senior Kevin Arbet was projected as a starting cornerback before he broke a bone in his foot during training camp, and junior transfer Ronald Nunn started the first three games at cornerback before he suffered a season-ending knee injury that required surgery.
Redshirt freshman William Buchanon switched from receiver to cornerback and started three games. Freshman Justin Wyatt was a backup.
"We head into the off-season and recruiting season with all the momentum we could ever want," Carroll said. "SC is a powerful place to recruit.... That's why we feel like we're just getting started."
USC's victory over Iowa drew a 14.8 Nielsen rating in Los Angeles and a 24% share of the audience.
The Rose Bowl on New Year's Day got a 14.4 rating and a 28 share in L.A.
The Orange Bowl overnight national rating was a 10.3 with a 16 share, which is 8% higher than the 9.5/15 overnight numbers for last year's Orange Bowl between Maryland and Florida.
Staff writer Larry Stewart contributed to this report.