Professional career Seattle Seahawks Robertson signed with the Seattle Seahawks as an undrafted free agent on May 9, 2016. He was waived by the Seahawks on August 30, 2016. Washington Redskins On January 6, 2017, Robertson signed a reserve/future contract with the Washington Redskins. He was waived by the Redskins on September 2, 2017 and was signed to the practice squad the next day. He was promoted to the active roster on November 21, 2017. He was waived by the Redskins on December 4, 2017 and re-signed to the practice squad. He was promoted again to the active roster on December 12, 2017. On September 1, 2018, Robertson was waived for final roster cuts before the start of the 2018 season. Arizona Cardinals On December 19, 2018, Robertson was signed to the Arizona Cardinals practice squad. He signed a reserve/future contract with the Cardinals on December 31, 2018.