The Tampa Bay Buccaneers will have to reserve some cash to sign their rookies, but it won't cost them much. According to Yahoo!'s Brian McIntyre, the Buccaneers have the lowest rookie salary pool in the NFL this season. The NFL has a strict rookie salary cap in place that effectively acts as a system of slotting rookie salaries according to draft position. The Bucs will spend between $3,338,674 and $3,018,242 on rookie salary cap space this season.
The fact that the Buccaneers have the lowest rookie salary pool shouldn't be very surprising: the Bucs didn't have a first-round pick, and made just six picks in all during the draft. This is actually relatively good news for the Buccaneers, as it will allow them to save some money for the cap problems they may face next season. In fact, the Buccaneers will be able to save money by signing these rookies.
Those rookies would displace at minimum the Bucs' six cheapest players on the roster, and likely displace a few more expensive ones too. And by my calculations, the six cheapest players on the 53-man roster would count for $3,348,750. That amounts to savings of just over $10,000 this season. That will help counterbalance the presence of multiple very expensive veterans on the roster, especially so if some of those rookies can take on significant roles.
Right now the Buccaneers have around $19 million in cap space, but they're expected to re-sign Mike Williams to a more expensive new contract, while they also need more room to operate during the season to replace players placed on injured reserve.