Beckwith will miss the early stages of training camp but can be activated at any time. However, he could also stay on the NFI list when the regular season begins.
Beckwith played in 16 games last season, and he started nine of them. He totaled 73 tackles and had one sack.
The Buccaneers also announced they signed safety Josh Liddell and defensive end Kiante Anderson to bring their roster to 90 players for training camp.
Anderson played collegiately at East Carolina, where he totaled 55 tackles, including 11 for loss and five sacks.
Liddell was originally signed by Tampa Bay as a college free agent out of Arkansas earlier this offseason, before being waived in May.