The Dallas Cowboys are conducting due diligence on Amari Cooper in consideration of a trade.

Cooper is believed to be on the trade block by the Oakland Raiders.

Washington and the Indianapolis Colts have also reached out to the Raiders on Cooper.

The Cowboys traded first-, third-, sixth- and seventh-round picks to the Detroit Lions in 2008 for wide receiver Roy Williams.

Cooper is in the NFL's concussion protocol, but the Raiders are on a bye this week and don't play again until Oct. 28 against Indianapolis.