The idea that the Bucs want to keep Bowers doesn't really fit with how they used him last year. The defensive end was primarily used as a backup three-technique defensive tackle and spent much of the year being inactive. He did get a decent amount of playing time over the last few weeks of the season, when Gerald McCoy was injured, and he played reasonably well then.
Bowers was a second-round pick for the Bucs in 2011 and,was supposed to help revitalize the team's pass rush, but he only ever flashed his potential. Injuries hampered him throughout his career, and as a result he has just 7 sacks over 50 games in four years. Still, he does still have potential, which might be why Tampa Bay wants him back -- at a reasonable price.