He played college football for the South Dakota State Jackrabbits and was signed by the Seattle Seahawks as an undrafted free agent after the 2024 NFL draft.
[1][2] He committed to play college football for the South Dakota State Jackrabbits (SDSU).
[3] In the spring 2021 season, postponed from 2020 due to the COVID-19 pandemic, Greenfield started all 10 games while helping South Dakota State reach their first national championship, being named a first-team All-American by several selectors.
[2] He shifted to left tackle in 2022 and started all 15 games while adding the role of team captain, being named a first-team All-American while helping SDSU win their first national championship.
[2][3][5] He returned for a final season in 2023 and won another national championship while starting all 15 games, receiving another All-America selection.