Hawthorne, 30, was entering the final year of his five-year, $19 million contract with the Saints and was set to make a base salary of $1,750,000 for the 2016 season.
According to OverTheCap.com, releasing will free up $2,250,000 in available cap space while creating $2,260,000 in dead money.
In 2015, Hawthorne appeared in 11 games and recorded 33 tackles and two forced fumbles for the Saints.
Humber, 28, signed a two-year, $2.085 million contract that included a $334,000 signing bonus with the Saints last year. He was set to make a base salary of $901,000 for the 2016 season.
In 2015, Humber appeared in 14 games for the Saints and recorded 47 tackles, one sack, and a pass defense.