Previous year stats show that approximately 200 drafted rookies make a roster each season, and a further 20 or so are kept on an injury exempt list. Additionally, about 60-70 UDFA stick on rosters or an exempt list. https://www.reddit.com/r/nfl/comments/2f1r8q/rookie_stats_for_the_initial_53_man_rosters/ In the year of this post, the grand total was close to 300 rookies across the league, or an average of 9 per team. In the Bucs case, I think they would be above that average, based on poor team performance in recent seasons, and a new coaching staff. However, Bruce Arians hates to play rookies and I could see him bringing in a couple veterans who've played for him in the past in lieu.
I'll settle on 10 rookies. At present, the 8 drafted players, White, Bunting-Murphy, Dean, Edwards, Nelson, Gay, Miller, Beckner, as well as UDFA Zack Bailey and Nick Fitzgerald. What you think?