Knox was originally signed by the Seattle Seahawks as an undrafted free agent on June 15, 2012. He was waived during final roster cuts on August 31, 2012.[2]
Knox was later signed to the Seahawks' practice squad for the final two weeks of the 2012 NFL season. On August 26, 2013, he was cut by the Seahawks.[4]
Jacksonville Jaguars
Knox was claimed off waivers by the Jacksonville Jaguars on August 27, 2013.[5] He was waived on October 3, 2013.
New Orleans Saints
On October 23, 2013, Knox was signed to the New Orleans Saints' practice squad. On January 1, 2014, he was promoted to the Saints' active roster. On May 4, 2015, he was released by the Saints.
Dallas Cowboys
On June 2, 2015, Knox was signed by the Dallas Cowboys. On June 5, 2015, he was released by the Cowboys.
On June 29, 2015, he was suspended by the NFL for the first four games of the 2015 season. However, no reason was given.[6]