Bush won the Heisman Trophy as college football's best player in December, and likely will be the first player chosen in the draft.
"He's ready for the next level," USC Coach Pete Carroll told the Los Angeles Times. "We all wish him the best and thank him for his contributions to our program. He's such a special player, a once-in-a-lifetime talent. He's a game-changer with his speed, instincts, vision and competitiveness. He's just so much fun to watch."
Bush compiled 2,890 all-purpose yards as a running back, kickoff returner and punt returner. He rushed for 1,740 yards and 16 touchdowns while making 37 receptions for 478 yards and two scores.
Bush also was named the Walter Camp Football Foundation's Player of the Year and won the Doak Walker Award, given to the nation's top running back.