Amerson, 27, had been expected to start at one of the team's cornerback spots with Patrick Peterson suspended for the first six games of the season for a violation of the league's performance-enhancing drug policy. Robert Alford, who signed a three-year contract with the Cardinals earlier this offseason, is expected to start at the other cornerback spot.
Amerson's release makes room for rookie cornerback Byron Murphy, whom they selected with the first pick of the second round of the 2019 draft, to make a push for the second starting cornerback spot while Peterson is out. Arizona also has veterans Tramaine Brock and Brandon Williams, along with a trio of young players -- Chris Jones, Deatrick Nichols and Nate Brooks -- on their on their depth chart.
The move to release Amerson, who signed with the team last November, was unexpected because he ended last season as the starter opposite Peterson, starting five of the six games he appeared in. With the signing of Alford in February, Amerson's role in 2019 was uncertain, but after Peterson's suspension was announced, it was widely expected he'd be in the mix to start the beginning of the 2019 season.
The six-year veteran has appeared in 74 games (61 starts) for three teams in his NFL career.
He has nine interceptions, 65 passes defensed, two forced fumbles and 273 tackles since the Redskins selected him in the second round (51st overall) of the 2013 draft.
ESPN's Josh Weinfuss contributed to this report.