Nichols spent the past few months in the XFL, leading the league with three interceptions for the Houston Roughnecks.
Nichols was a standout at South Florida, totaling 11 interceptions in his final three seasons before trying to make it in the NFL as an undrafted free agent.
Though he signed with the Arizona Cardinals, he mostly spent time in the practice squad before playing two games with the team in 2018. Per Pro Football Reference, he played 11 snaps on special teams and zero on defense.
Despite his limited action as a professional, he was a ninth-round draft pick in the XFL and played well before the league shut down due to the coronavirus.
The 25-year-old totaled 24 tackles and a sack to go with his three picks.
Nichols will try to take advantage of his second chance with the Saints, a team that finished 11th in yards allowed per pass attempt in 2019.