vi quoto un estratto del regolamento sui free agent
Unrestricted Free Agents (UFA) are players who have completed four or more accrued seasons of service and whose contracts have expired. They are free to sign with any club through July 22 (or the first scheduled day of the first NFL training camp, whichever is later). On July 23, their exclusive rights will revert to their original club if that club made a June 1 tender to these players. Teams will have until the Tuesday after the 10th week of the season (November 14) to sign their unrestricted veteran free agents to whom a tender was made on June 1. If the player does not sign by November 14, he must continue to sit out the remainder of the season. If a June 1 tender is not made to a UFA, he continues to be free to sign with any club.
Restricted Free Agents (RFA) are players who have completed three accrued seasons of service and whose contracts have expired. They have received qualifying offers from their old clubs and are free to negotiate with any club until April 21, at which time their rights revert to their original club. If a player accepts an offer from a new club, the old club will have the right to match the offer and retain the player. If the old club elects not to match the offer, it may receive draft-choice compensation depending on the level of the qualifying offer made to the player.
nel calcio non ci sono le scelte, però si possono prevedere altri tipi di compensazione, quali soldi, giocatori o opzioni su altri calciatori.
come principio non mi sembra sbagliato, e non lo vedo così inattuabile nel calcio.