 Clowney was claimed off waivers by the Carolina Panthers on October 5, 2010.On September 4, 2011 Clowney was cut by the Panthers

On January 5, 2012 Clowney signed a future contract with the Buffalo Bills, the contract saw Clowney earn $700,000 in 2012 until he was released by the Bills during the 2012 season.Clowney was signed by Montreal Alouettes of the (CFL) Canadian Football League on November 12, 2012.