Griggs was disciplined “pending resolution of a student conduct matter,” according to a statement released by the university’s athletic department.
Last season, Griggs appeared in 10 games, making seven starts, for the Golden Eagles. He passed for 1,879 yards while throwing for 16 touchdowns versus only two interceptions.
The 6-foot-3, 225-pound Griggs also is a threat to run, rushing for 268 yards and three touchdowns in 2017.
Griggs sat out spring practice while rehabbing from surgery on his Achilles, according to the Hattiesburg (Miss.) American.
Junior college transfer Jack Abraham, a former Gatorade Player of the Year in Mississippi, has the most experience of the other quarterbacks on the roster.
Other potential quarterback options for Southern Miss are freshmen Marcelo Rodriguez and Tate Whatley.