The NFL Supplemental Draft offers prospects who missed the original filing deadline of the regular draft, for whatever reason, an opportunity to still be selected by teams. In a silent auction of sorts, teams, including the Carolina Panthers, can place bids on the players available and the highest adds them to their roster in exchange for that round pick in the following draft.
For example, if a prospect receives two bids from different NFL franchises of a third-round and fourth-round pick, then the team placing the third-round designation on the player wins. They then forfeit their third-round pick from the next NFL Draft.