In any sport, one of the keys to building a successful team is to make sure you have depth and the ability to adapt to injuries. Hayward is not good enough to be a starting player, but he provides the Bucs with a reliable option as a backup in case of injury. Last season he had to fill in when Quincy Black got injured, and the Bucs defense was able to keep going without missing a beat.
The Bucs appear to be finished making big signings, and as Bucs Nation points out, they now have plenty of depth at linebacker:
By signing Hayward the Bucs have rounded out their linebacking corps, which now consists of Quincy Black, Tyrone McKenzie, Geno Hayes, Mason Foster, Dekoda Watson and Adam Hayward. The Bucs also have undrafted rookies Nick Reveiz, Derrell Smith, Victor Aiyewa and Brandon Heath, as well as practice squad player Lawrence Simoni. Those players will have to excel on special teams to make the roster, and Derrell Smith and Nick Reveiz stand a decent chance of making it to the practice squad.