Rapp started his NFL career with the Los Angeles Rams in 2019, and Buffalo signed the safety to a one-year deal in 2023.
He spent three seasons as a Bill, logging 158 tackles, eight passes defensed, three interceptions, three tackles for loss, one forced fumble, one fumble recovery, one quarterback hit and a half-sack over 36 games and 24 starts.
Buffalo placed Rapp on injured reserve on Oct. 24, 2025, due to a lingering knee injury that affected him throughout training camp. He played and started in six games in 2025, making 26 tackles.
Over his seven-year career, Rapp registered 488 tackles, 31 passes defensed, 12 interceptions, 11 tackles for loss, six quarterback hits, four fumble recoveries and two forced fumbles.
Rapp was a second-round draft pick out of Washington in the 2019 NFL Draft, going 61st overall to the Rams.