"All three guys showed tremendous improvement and development, which is a credit to their hard work and the work of (quarterbacks coach) Dan Enos and his offensive staff," head coach Manny Diaz said in a statement.
Diaz said his next decision will be to decide between Martell or Perry for primary backup duties.
Williams is a four-star recruit out of Georgia. The dual-threat QB played in just one game in his true freshman season.
Martell transferred after two campaigns at Ohio State. Perry played in 11 games last season for the Hurricanes, completing 50.8 percent of his passes for 1,091 yards, 13 touchdowns, and six interceptions.