At Missouri Western, Grandy transitioned to being a tight end.[5][6] As a freshman for the Griffons in 2018, he appeared in eight games, recording six receptions for 65 yards and a touchdown, and the following year, he played in all 12 games, four as a starter, and caught 20 passes for 261 yards and five touchdowns, being named honorable mention All-Mid-America Intercollegiate Athletics Association (MIAA).[7] The 2020 season was canceled due to the COVID-19 pandemic, and Grandy did not play in the 2021 season, before returning in 2022 and catching 31 receptions for 275 yards while being named second-team All-MIAA.[7]
Grandy transferred to the NCAA Division I FCSIllinois State Redbirds for a final season in 2023.[8] He started all 11 games for the Redbirds, totaling 63 receptions for 612 yards and three touchdowns, being named first-taem All-Missouri Valley Football Conference (MVFC), a consensus first-team FCS All-American, to the MVFC All-Newcomer team and the Illinois State Male Athlete of the Year.[2]
After going unselected in the 2024 NFL draft, Grandy signed with the Cincinnati Bengals as an undrafted free agent.[4] He was released on August 27, 2024, then re-signed to the practice squad the following day.[10] He was elevated to the active roster on November 7, 2024, for the team's Week 10 game against the Baltimore Ravens, and made his NFL debut in the game.[1][11] On November 15, Grandy was signed to the active roster.[12]