Pryor attended the camp on a tryout basis. He has a connection with offensive coordinator Hue Jackson, who was his head coach in Oakland in 2011.
The former Ohio State quarterback started 16 games during three seasons with the Raiders.
The Bengals also signed seventh-round pick Mario Alford, a receiver from West Virginia; safety Erick Dargan from Oregon; defensive tackle Kalafitoni Pole from Washington State, and tight end John Peters from Mount St. Joseph's.
Tight end Kevin Brock, who played in 14 games last season with five catches, was released.
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