EnterSports Management also announced that the Bills signed their client, OL Tyler Gauthier, to a contract.
Harrell, 23, wound up going undrafted out of Auburn back in 2020. He later signed a rookie contract with the Bills but was waived coming out of training camp.
The Bills signed Harrell to their practice squad before eventually releasing him in January. He caught on with the Raiders in May but was cut loose last month.
During his college career at Auburn, Hall was a two-year starter and was named third-team All-SEC. He appeared in 43 games, making 31 starts.