O'Brien is among a list of 24 players invited to attend the Falcons' rookie minicamp on a tryout basis, the team announced.
O'Brien, who transferred from Wisconsin for his junior season after two seasons at Maryland that included being named the 2010 Atlantic Coast Conference Rookie of the Year, finished his career at Division II Catawba last season.
He completed 68 percent of his throws for 2,490 yards and 15 touchdowns with six interceptions at Catawba.
O'Brien left Wisconsin after playing in seven games, completing 52 of 86 passes for 523 yards, three touchdowns and one interception.
At Maryland, O'Brien passed for 2,438 yards and 22 touchdowns as a freshman.
As a sophomore for the Terps, he started seven games and passed for 1,648 yards and seven touchdowns before leaving the program.