Brock, 28, was set to be an exclusive rights free agent in the coming weeks. He originally signed on with the Panthers as an undrafted free agent out of Rutgers back in 2009.
Brock has since played for the Jets, Steelers, Bears, Cowboys, Raiders, Bills, and Chiefs before joining the Bengals in December of 2013.
This season, Brock appeared in 14 games and caught five passes for 21 yards receiving for the Bengals. Pro Football Focus has him down for playing 156 snaps this season.