Spillane began his football career by playing college football at Western Michigan University. After going undrafted in the 2018 NFL Draft, he signed with the Tennessee Titans as an undrafted free agent. However, he was waived by the Titans during the preseason and was later signed to the practice squad of the Pittsburgh Steelers. In 2019, Spillane was promoted to the active roster and made his NFL debut with the Steelers.