At the 2009 NFL Scouting Combine, Arnoux ran the second fastest 40-yard dash time at the linebacker position. His official 40-yard dash time was 4.61 seconds.
Arnoux was drafted by the New Orleans Saints in the fourth round of the 2009 NFL draft with the 118th overall pick.[3] In the first practice of Saints rookie minicamp, Arnoux tore his left Achilles tendon. He missed the entire 2009 season due to the severity of the injury. He was signed to a four-year contract on September 7, 2009, and immediately placed on injured reserve due to his injury.[4] In 2010, he was on the active roster for the Saints' first 10 games, but suffered another Achilles tendon injury in a game against Seattle, and was placed on the injured reserve list on November 23, 2010.[5]
He was released by the Saints on July 29, 2011.[6]