Diaby attended Georgia Military College for two years before transferring to the University of Louisville.[2][3] He had 77 tackles and seven sacks at Georgia Military.[4] In Diaby's first year at Louisville in 2020, he started seven of eight games, recording 18 tackles.[5] In 2021, he had 39 tackles and 1.5 sacks.[6] In 2022, Diaby had 37 tackles and nine sacks.[7] After the season, he entered the 2023 NFL draft.
Diaby was drafted by the Tampa Bay Buccaneers in the third round of the 2023 NFL Draft with the 82nd overall pick.[10] As a rookie, Diaby played in all 17 regular season games and made seven starts. He finished with 38 total tackles (25 solo), one forced fumble, and two fumble recoveries. He started both of the Buccaneers' postseason games.[11]
In Week 18 of the 2024 season, Diaby recorded five tackles, four for a loss, and one sack in a 29-17 win over the New Orleans Saints, earning NFC Defensive Player of the Week.[12]