After playing four years at Oregon, Mondeaux was signed by the New Orleans Saints as an undrafted free agent on May 7, 2018.[3] He was waived on September 1[4] and signed to the practice squad on December 31, where he spent the rest of the season.[5]
Kansas City Chiefs
On January 26, 2019, Mondeaux signed with the Kansas City Chiefs on a reserve/future deal[6] and was waived on May 3.[7]
Pittsburgh Steelers
On May 13, 2019, Mondeaux signed with the Pittsburgh Steelers after a tryout,[8] but was waived on August 31.[9] A day later, he was signed to the Steelers' practice squad, where he spent the entire season.[10]
On December 30, 2019, Mondeaux re-signed with the Steelers to a reserve/future contract,[11] but was waived on September 5, 2020[12] and subsequently signed to the practice squad.[13] On October 23, he was promoted to the active roster.[14]
On September 3, 2021, Mondeaux was waived by the Steelers and re-signed to the practice squad.[15][16] On September 20, 2021, Mondeaux was promoted to the active roster after an injury to Tyson Alualu.[17]
On August 30, 2022, Mondeaux was waived by the Steelers.[18]
New York Giants
On September 1, 2022, the New York Giants signed Mondeaux to their practice squad.[19] Mondeaux was elevated from the practice squad for Week 3 and Week 4 games against the Dallas Cowboys and Chicago Bears.[20][21] He was elevated from the practice squad for the third time this season for Week 10 game against the Houston Texans.[22] He was promoted to the active roster on November 14.[23]
Jacksonville Jaguars
On March 27, 2023, Mondeaux was signed by the Jacksonville Jaguars.[24] He was placed on injured reserve on August 14, 2023.[25] He was released on August 22, and re-signed to the practice squad on October 23.[26] He was not signed to a reserve/future contract and thus became a free agent after the season when his practice squad contract expired.[27]