Sargent was signed as an undrafted free agent by the St. Louis Cardinals after the 1986 NFL draft on May 19.
Sargent crossed the picket line to be a part of the Cardinals replacement team, that was given the mock name "Crudbirds" by the media.
In the fourth game against the Washington Redskins, he posted 78 yards rushing, including 70 in the first half.
In the twelfth game against the Philadelphia Eagles, he was the team's leading rusher, including a career-long 43-yard run.
On September 3, 1990, he was released after being passed on the depth chart by Tommie Agee for the backup fullback position.