[1] Due to the effects of Hurricane Katrina along the Mississippi Gulf Coast in the summer of 2005, Armstrong evacuated to San Antonio, Texas to live with his younger brother and father.

Armstrong attended Steele High School in Cibolo, Texas, a suburb 15 miles northeast of San Antonio.

[9] As a dual-threat quarterback, Armstrong sought to join the National Football League (NFL) by changing positions.

Armstrong was subsequently given a tryout with the Minnesota Vikings as a running back, but was later asked to sign as a safety, a defensive position and one he had not played since high school.

On September 9, 2018, Armstrong announced via his Twitter account that he had signed with the Salt Lake Stallions of the Alliance of American Football for the 2019 season.

Armstrong was named the IFL Offensive Player of the Week for his performance in his professional debut.

[15][16] Armstrong played in all 14 regular season games for the Danger, leading them to a playoff berth, finishing with a 7–7 record in 5th place.

[17] On June 21, 2019, Armstrong led the Danger to a 45-40 playoff win over the Green Bay Blizzard before suffering a 62–45 defeat at the hands of the Arizona Rattlers.

On November 10, 2023, Armstrong re-signed with the Beef for their first season in the National Arena League (NAL).