After playing for Boston College from 2014–2017, Hilliman graduated and transferred to Rutgers as a graduate transfer.[3] He led the team in rushing touchdowns as a redshirt senior at Rutgers.[4]
After going undrafted in the 2019 NFL draft, Hilliman signed with the New York Giants.[5][6][7] He was waived on August 31, 2019, and was signed to the practice squad the next day.[8][9] He was promoted to the active roster on September 26, 2019.[10] Hilliman made his first start with the Giants in Week 6 against the New England Patriots due to injuries suffered by starter Saquon Barkley and his backup Wayne Gallman. In the game, Hilliman rushed 11 times for 38 yards and lost a fumble when Jamie Collins stripped the ball out and Kyle Van Noy returned it for a touchdown in the 35–14 loss.[11] Hilliman was waived by the Giants on October 11, 2019, in order for them to sign veteran running back Javorius Allen,[12] and later re-signed to the practice squad.[13] He signed a reserve/future contract with the Giants on December 30, 2019.[14] He was waived on August 2, 2020.[15]