Major League Baseball transactions are changes made to the roster of a major league team during or after the season. They may include waiving, releasing, and trading players, as well as assigning players to minor league teams. Active, expanded, and postseason rosters As of the 2022 season, each Major League Baseball team maintains a 26-man active roster, a 28-man expanded roster, and a 40-man reserve list of players. Players on the 26-man roster are eligible to play in official major league games throughout the season. The 40-man reserve list includes the players on the 26-man roster plus as many as 14 players who are either on the team's seven-, ten-, fifteen-, or 60-day injured list, who are on paternity leave for up to three days, or who are in the franchise's farm teams in Minor League Baseball. From September 1 through the end of the regular season, each team is required to expand its active roster to 28 players. (Before the 2020 season, any player on the 40-man reserve list, also referred to as the "expanded roster", was eligible to play in an official regular season game on or after September 1.) Many young players make their Major League debuts in this way, as "September call-ups." To be eligible for a team's postseason roster, a player must be on any of the following: (a) the 40-man reserve list, (b) the injured list, (c) the bereavement list, or (d) the restricted list as of August 31 at midnight ET. The only exception is that a player who is on the injured list at the end of the regular season may be replaced on the postseason roster by any other player who was in the organization on August 31, with the approval of the Commissioner. All players on the team's roster during the season will be eligible to receive a World Series ring after the team wins the World Series. The August 31 rule was waived in for servicemen returning from World War II. Over the years, there have been several notable cases where a player acquired after the August 31 deadline made a significant contribution to a playoff-contending team but was ineligible for the postseason; for example, Pedro Ramos with the 1964 New York Yankees and Sparky Lyle with the 1980 Philadelphia Phillies. Trades Teams may trade only players currently under contract. Trades between two or more major-league teams may freely