Some, such as quarterback Matt Leinart and defensive linemen Frostee Rucker and LaJuan Ramsey, will not be back because they're seniors. And some juniors, such as Reggie Bush, LenDale White, Darnell Bing and Winston Justice may not return if they make themselves available for the NFL draft.
An end of an era for most, but not for USC Coach Pete Carroll, who began looking ahead to next season when he had the Trojans spend a great deal of practice time working with unproven underclassmen entering this year's Rose Bowl.
"We feature our young guys, really give them an opportunity to push to the front in preparation for spring football," Carroll said this week. "To get a look at guys in positions, move some people around, really just doing football things, just working at your game."
It's this philosophy that helped the Trojan defense bounce back after losing starters Shaun Cody, Manuel Wright, Mike Patterson, Lofa Tatupu, Matt Grootegoed, Jason Leach, Eric Wright, Kevin Arbet and Ronald Nunn from last season's national championship team.
Next fall, the focus will be on an offense that's expected to lose a ton of talent and leadership.
The spotlight will be on quarterback, a position Leinart dominated the last three seasons. The Trojans expect a heated competition between sophomore John David Booty and redshirting freshman Mark Sanchez. Based on the skills and competitiveness of each, the battle could drag into fall camp.
Booty, 6 feet 3, 195 pounds, is the first Division I-A football player to graduate a full year early from high school and enroll at a major university. He is considered the front-runner because he has been in the system for three years.
Sanchez is bigger (6-4, 215) and ran USC's scout team for much of the season. He was the 2004 Parade magazine high school player of the year after leading Mission Viejo to an unbeaten season and has impressed Trojan coaches with his growth.
If Bush and White jump to the NFL, the competition at running back will be open. Desmond Reed, the No. 3 back before suffering a season-ending knee injury at Notre Dame, will be in the mix along with freshman Michael Coleman and probably sophomore Chauncey Washington.
Coleman, who rushed for 95 yards in 20 carries before being sidelined because of a hip injury in late October, turned heads imitating Texas' Vince Young in preparation for the Rose Bowl.
"He's been banged up throughout the season, but he's back now and did a fine job," Bing said of the 6-1, 235-pound Coleman. "He's a big back, who also has speed and likes to run people over."
Washington is the mystery back. He was a standout runner last spring but has been academically ineligible the last two seasons.
But even if Coleman and Washington are ready to step up and Reed is back at full strength, there's always the possibility of USC's adding freshmen to the group.
"I think that we have come to a point with our freshmen that our expectations are so high," Carroll said. "They're expected to come in and play."
And there's no promise that White will leave. He said after Wednesday's game, "I haven't made any decision. I know it's a lot of fun to play with these guys and on this team and it will be hard to leave. I've got a lot of thinking to do, and I need to talk to my family.
"This decision can't be made on winning or losing one game."
Senior fullback David Kirtman has had a productive career, but if junior Brandon Hancock returns as expected, USC will not suffer much of a drop with sophomore Jody Adewale as his backup.
Sophomore wideout Dwayne Jarrett will return, and junior Steve Smith could also be back to give USC possibly the best receiving duo in school history. Throw in freshman Patrick Turner, who will play a bigger role, along with sophomore Whitney Lewis and junior Chris McFoy, and receiver will be a team strength.
At tight end, sophomore Fred Davis, who started three games this season, is ready to take over for senior Dominique Byrd. Junior Nick Vanderboom, sophomore Dale Thompson and redshirt freshman Jimmy Miller are also in the picture.
Although the offensive line has only one senior -- in starting guard Taitusi Lutui -- USC will probably lose Justice to the NFL, possibly along with junior center Ryan Kalil and junior guard Fred Matua. That would leave sophomore tackle Sam Baker -- a draft-eligible sophomore -- as the only returning starter.
However, after Wednesday's game, Matua first guaranteed the Trojans would play for a national championship again next season, then said he'd be back to enjoy it.
"I can't see myself leaving these guys right now," he said. "I'll talk to my family and think about what I want to do, but I just can't see leaving.".
Justice was more noncommittal. "I'm not ready to make a decision yet. Winning or losing tonight doesn't make a difference. There's a lot that goes into making a decision like this. I just have to sit down with everybody that matters and talk and listen."
If that's the case, line coach Pat Ruel will have his hands full building a new unit with the return of sophomore Jeff Byers, who started four games at guard in 2004 but redshirted this season because of injury. He'll also have untested blockers Kyle Williams, Alatini Malu, Chilo Rachal and redshirting freshmen Thomas Herring and Nick Howell.
During the regular season, the Trojans had the injury bug at linebacker. Fall camp starters Dallas Sartz, Keith Rivers and Oscar Lua each missed time because of injuries, with Sartz sitting out the season.
That opened the door for freshmen Brian Cushing and Rey Maualuga to get playing experience and for sophomore Thomas Williams to emerge as a key playmaker. Carroll expects all six linebackers to compete for minutes next season.
"We pass that message on to them clearly through the recruiting process," he said. "It's not a recruiting ploy; I want them to come in with the mind-set that they have to prepare to play, and our coaches think exactly the same way."
The defensive line will be led by sophomore end Lawrence Jackson and sophomore nose tackle Sedrick Ellis. They will probably be joined by Fili Moala or Travis Tofi at tackle, with Jeff Schweiger, Kyle Moore and Alex Morrow among the players competing to replace Rucker at end.
Senior defensive backs Scott Ware, Justin Wyatt and John Walker will be missed, and Bing, a three-year starter, is expected to go pro. Normally, that would be a problem, but Carroll, who also serves as coordinator, has been through this before.
So look for him to shape the secondary around sophomore Josh Pinkard, who began the season at safety but ended starting at cornerback, along with freshman safety Kevin Ellison and sophomore cornerback Terrell Thomas, who were starters before suffering season-ending knee injuries.
Other defensive backs expected to compete for playing time next season include freshmen Cary Harris, Kevin Thomas and Will Harris, along with sophomore junior college transfer Mozique McCurtis and the junior Ting twins, Ryan and Brandon.
USC will have to replace senior punter Tom Malone, but sophomore kicker Mario Danelo will return for Carroll, who said that he's excited about next season's reloading project.
"Years ago when I was in the NFL coaching, I would have fought every GM and player personnel guy not to play rookies because of the old mind-set that they're going to make mistakes and get you beat," Carroll said. "I don't see it that way anymore. I see it the opposite, that you need to take your guys and push them to the front and have them live with expectations that they're going to play."
Times staff writer Diane Pucin contributed to this report.