[1] Kelly was signed by the New Orleans Saints as an undrafted free agent following the 2019 NFL draft on April 27, 2019.
[3][4] Kelly signed a reserve/futures contract on January 6, 2020, and made the Saints' active roster coming out of training camp the next season.
[5][6] Kelly made his NFL debut on September 13, 2020, in the season opener against the Tampa Bay Buccaneers.
[17] Kelly was placed on the reserve list by the San Antonio Brahmas of the XFL on March 7, 2023, and activated on April 7.
[20] On January 19, 2024, Kelly re-signed with the San Antonio Brahmas of the United Football League (UFL).