The reserve clause, in North American professional sports, was part of a player contract which stated that the rights to players were retained by the team upon the contract's expiration. Players under these contracts were not free to enter into another contract with another team. Once signed to a contract, players could, at the team's whim, be reassigned, traded, sold, or released. Once common in sports, the clause was abolished in baseball in 1975. The reserve clause system has, for the most part, been replaced by free agency.