Milligan has also been a member of the Dallas Cowboys, Detroit Lions, and Indianapolis Colts.

Milligan attended Lake Wales High School, where he played as a quarterback.

He transferred to the University of Toledo after UAB announced the cancelling of its football program.

Milligan was signed as an undrafted free agent by the Dallas Cowboys after the 2016 NFL draft on May 9.

[8] On September 1, 2018, Milligan was waived by the Lions and was signed to the practice squad the next day.

[14] He was promoted to the active roster on December 22, 2018, but was waived six days later and re-signed to the practice squad.

[23] On October 24, 2021, Milligan signed with the Saskatchewan Roughriders of the Canadian Football League (CFL).

[25] Milligan played in the first four games of the 2023 season before suffering a season-ending toe injury.