Nicholas has spent his entire NFL career with the Falcons since being picked by the franchise in the fourth round of the 2007 NFL Draft. He has played in 101 games, totalling 397 tackles, 10 sacks, two interceptions, five forced fumbles, and 12 passes defended.
Samuel, meanwhile, has been in the league since 2003, and joined the Falcons from the Philadelphia Eagles in 2012. In two seasons in Atlanta, he recorded 70 tackles, six interceptions and 20 passes defended.
The Falcons are expected to save over $4m (£2.45m) by releasing 33-year-old Samuel, who had been replaced by rookie Robert Alford towards the back end of last season.