Armstead was part of a highly talented team that featured four other future NFL players—Clifton Abraham, Joe Burch, Le'Shai Maston, Darius Smith—and won the 1988 5A state championship (which was later stripped by UIL in 1991 due to eligibility infringements), defeating Permian High School in the state semi-final game, which was portrayed as the state championship game in the 2004 film Friday Night Lights and the 2017 ESPN 30 for 30 documentary "What Carter Lost" as well as the 2015 film Carter High.

Fellow D-I recruits Derric Evans and Gary Edwards asked Armstead to join them and others in a series of robberies of video stores and fast-food restaurants, but he refused.

A college standout on 2 of Miami's 5 national championship teams (1989, 1991), Armstead's pro prospects were diminished after he tore his anterior cruciate ligament his sophomore season.

Following a nine-year career with the Giants, he was signed to a three-year, $10.5 million deal by the Washington Redskins, where he played for two additional seasons.

His responsibilities include special projects, defensive assignments, player development and free agent recruiting.