<P> The intent of the rule 5 draft is to prevent teams from holding major league - potential players in the minor leagues when other teams would be willing to have them play in the majors . However, this draft has also become an opportunity for a team to take a top prospect from another team who might not be ready for the major leagues . For example, Cy Young award winner Johan Santana was chosen by the Florida Marlins four years before winning the award, when the Houston Astros declined to put him on their 40 - man roster . The Marlins chose Santana in the 1999 rule 5 draft, and traded him to the Minnesota Twins who kept him on their roster for the 2000 season, in which he toiled to a 6.49 earned run average at only 21 years of age . Two years later, he legitimized himself as a Major League pitcher, with an ERA under 3.00, and two years after that, he was recognized as one of the best pitchers in the league . Had he not been chosen in the rule 5 draft, he likely would not have made his major - league debut until the 2001 or the 2002 season with the Astros . </P> <P> Roberto Clemente is the only Rule 5 draft pick to be inducted into Cooperstown, having been selected by the Pittsburgh Pirates from the then Brooklyn Dodgers in 1955 . </P> <P> A free agent is a player whose contract with a team has expired and who is thus eligible to sign with another team . </P> <P> If a player is drafted and is offered a contract by his drafting team (or any team to which he is traded) each year, he may not become a free agent until: </P>

When does an mlb player become a free agent