STATE COLLEGE, Pa. (AP) – Penn State's loss could turn into a big gain on the ground for Southern California.

Star tailback Silas Redd bolted Happy Valley to join the Trojans in a season of great expectations in Los Angeles. A 1,200-yard rusher, Redd will join heralded quarterback Matt Barkley on a team already favored to win the Pac-12 and return to the Rose Bowl.

It's a perk that Redd wouldn't have enjoyed at Penn State with the program burdened by stiff NCAA sanctions because of the Jerry Sandusky child sex abuse scandal. Among the penalties was a four-year postseason ban, as well as a scholarship reduction.

The NCAA also allowed players to seek new schools to play immediately this season, so long as they left by the start of Penn State training camp on Monday.

Since the sanctions were imposed last week, Nittany Lions coach Bill O'Brien has been trying to keep the team intact by stressing academics, family and the prospect of playing seven home games a year in front of a crowd of 108,000 strong at Beaver Stadium.

For the most part, it seems to have worked – even though Redd's departure will be a serious blow to an offense being reconfigured by O'Brien, the former coordinator of the New England Patriots' high-powered attack.

Counting Redd, three players have left Penn State since the NCAA imposed its landmark sanctions on July 23. A fourth player, third-string quarterback Rob Bolden, was removed from the roster this week but had been granted permission to talk to other schools before the sanctions.

Otherwise, O'Brien hasn't lost any other starters or top backups so far. He had also said last week at Big Ten media days that more than 50 players had indicated they would stay. Six 2013 recruits have also reaffirmed their verbal commitments.

Penn State athletic director Dave Joyner wished Redd and the other transfers well. "I think that certainly we understand and it's within their purview," Joyner said in an interview Tuesday night with The Associated Press at an evening football function.

He added the low number of transfers was "a great testament to Bill O'Brien, and the kind of person he is, the kind of coach he is and the kind of players these are overall.

"This team has a lot of unity."

But it won't have Redd. Sophomore Bill Belton, a converted wideout, is next on the Penn State depth chart, and that could prove to be a roadblock as O'Brien tries to transform the offense on the fly.

Out west, Redd joins a team that finished 10-2 and No. 6 in the final AP poll last season despite its own NCAA sanctions – bowl ineligibility and a smaller roster. After Barkley and safety T.J. McDonald decided in December to return for their senior years, USC signed a top-flight recruiting class led by elite quarterback prospect Max Browne.

Redd could make the Trojans even better.

"We welcome Silas Redd to the Trojan Family," USC athletic director Pat Haden said in a statement. "He is an outstanding student and athlete."

USC had been sanctioned for rules violations committed during the 2004 and `05 seasons.

"At USC, we've seen both sides of this issue, having lost a number of players to transfer due to our NCAA sanctions in 2010. But Lane Kiffin and his coaches would not be doing their job if they did not try to improve our team every single day," Haden said. "There is a specific need here for a player like Silas Redd, so Lane and our coaches recruited him within the guidelines set up in this instance by the NCAA."

An early-morning rally and last-minute social media campaign couldn't keep Redd from leaving Penn State. He took a weekend visit to USC before delivering the news to Nittany Lions coaches at the team headquarters – about 12 hours after Tuesday's "Rise and Rally" community event to rouse the players at morning workouts.

Penn State said later Tuesday that tight end Kevin Haplea was also no longer with the team. Haplea is off to Florida State. Others PSU players transferring are Kahairi Fortt (California), Tim Buckley (NC State), and Rob Bolden (LSU). Incoming freshman Jamil Pollard has decided to go to Rutgers.