Minor league Minor leagues are professional sports leagues which are not regarded as the premier leagues in those sports . Minor league teams tend to play in smaller , less elaborate venues , often competing in smaller cities . This term is used in North America with regard to several organizations competing in various sports . They generally have lesser fan bases and smaller budgets . The minor league concept is a manifestation of the franchise system used in North American sports , whereby the group of major league teams in each sport is fixed for long periods between expansions or other adjustments , which only take place with the consent of the major league owners . In England ( and many other countries ) , the football leagues have many divisions below the " top - flight " as part of the football pyramid . In other parts of the world there is usually either a system of annual promotion and relegation , meaning that clubs have no fixed status in the hierarchy , or there is only one professional league per country in each sport , rendering the major / minor distinction irrelevant . Baseball . Minor league baseball is almost as old as the professional game itself , and at first consisted of attempts to play baseball in smaller cities and towns independent of the National League , the first true major baseball league . Soon , scouts for the National League were travelling to watch minor league teams play and attempting to sign the more talented ones away . Some sports historians cite the connection between the other major league , the American League and its minor league forebear , the Western Association . Soon Major League Baseball began formal developmental agreements with some minor league teams , while others remained " independent " . The most prominent independent minor baseball league today is probably the Northern League . Ice hockey . The sport with the next most extensive system of minor league teams other than baseball is ice hockey . In North America , between 1988 and 2005 , 233 minor professional ice hockey teams played in a total of 160 cities in 13 minor professional leagues . The vast majority of these teams played in the United States , with only 21 of these teams based in Canadian cities . 123 of these minor professional teams played in the southern United States . One reason given for the large number of American based teams is that minor league franchises will frequently move from city to city , and even between leagues . The American Hockey League is the most prominent of the minor hockey leagues in North America . Other minor leagues include : Most National Hockey League teams have a farm team in the American Hockey League and often share a team in the ECHL . On " the farm " the NHL team will develop young players and , occasionally , rehabilitate older players who are injured or whose quality of play has slumped . These teams , in turn , have lower - level minor leagues to draw players from and pass players down to . Minor ice hockey leagues should not be confused with Junior or Senior ice hockey leagues . They are different in that minor professional hockey leagues do not have restrictions on the age or experience levels of their players , but Junior and Senior leagues do . Basketball . The National Basketball Association has an affiliated minor league , the NBA Development League ( also called the " D - League " ) . The now - defunct Continental Basketball Association ( CBA ) served some of the purposes of a minor league for the NBA for many years . However , there were no direct developmental agreements between CBA and NBA teams the way that there are between Major League Baseball and National Hockey League teams and their minor league affiliates . Association football . While Major League Soccer does not have any " affiliated " minor leagues , the United Soccer Leagues contains two separate divisions of professional teams , USL - 1 and USL - 2 ( which also do not have a promotion and relegation system ) . These two divisions serve as the second and third levels of the American soccer pyramid . The USL also contains the Premier Development League , a semi - professional league that has some age restrictions . American football . While there are various semi - professional football leagues , none have any affiliation with the National Football League . The NFL and its teams have had working relationships with several independent leagues in the past , including the Association of Professional Football Leagues , the Atlantic Coast Football League , and most recently , the league owned - and - operated NFL Europe League . Many considered the now - defunct Arena Football League to be a minor league , since several NFL owners had teams in it , but this is not exactly the case . Arena Football is played under very different conditions , and the AFL had survived for 22 seasons before going bankrupt in 2009 ; since 2000 , the AFL had its own minor league , af2 . When the AFL went bankrupt and af2 disbanded , the surviving teams joined a new league known as Arena Football 1 , which has no NFL - tied owners and will begin play in 2010 . Several other independent indoor football leagues that play a similar game exist . Similarly , the Canadian Football League , though it has developed ties with the NFL in recent years and has moved away from competing with the NFL for talent , plays a visibly different game than the American game , and the two sports favor different types of skills . Several minor and developmental leagues independent of the NFL have come and gone ; there are currently three that are in development — the UNGL ( purely a minor league ) , New USFL ( complementary , major / minor intentions not yet stated ) , and AAFL ( complementary league ) - - and one , the United Football League , which began play in 2009 as a complementary top - level development league . Other sports . Other sports organizations considered to be minor leagues are the golf Nationwide Tour , affiliated with the PGA Tour , NASCAR ' s Nationwide Series , Camping World Truck Series and Whelen All - American Series , and various other affiliated satellite tours of other individual sports , including the Challengers Tour of Professional Tennis .