Bailey, a redshirt junior, has one year of eligibility remaining at USC.
After USC's 45-20 win against Fresno State in the Las Vegas Bowl on Saturday, Bailey said the decision to stay at USC or announce for the NFL was a "win-win".
"If I leave, I graduated, I got my degree," Bailey said. "I made all-conference for two different positions. I mean, if I left early I wouldn't regret it at all."
Bailey redshirted his freshman season at USC. He started at strongside linebacker his second and third year before moving back to safety this year.
In 14 games played for the Trojans this season, Bailey finished fourth on the team with 62 tackles. He led the defense with a team-high five interceptions.
Bailey is just one of 32 draft-eligble players who could leave USC early. Also expected to make upcoming announcements about their football future is Marqise Lee, Josh Shaw, George Uko, Hayes Pullard, Marcus Martin, Randall Telfer, and Aundrey Walker.