Since "natural rivalry" matchups were part of the three-year divisional rotation, the schedule format for interleague games was different from previous years.
Under the new collective bargaining agreement reached in December 2016, the regular season was extended to 187 days in order to add four additional off-days for all teams.
[1][2][3] The Minnesota Twins and the Cleveland Indians played a two-game series at Hiram Bithorn Stadium in San Juan, Puerto Rico, on April 17 and 18,[4] while the Los Angeles Dodgers and San Diego Padres played a three-game series at Estadio de Béisbol Monterrey in Monterrey, Mexico, from May 4 to 6.
[6] Beginning in the 2018 season, MLB implemented new pace of play rules, which include limiting the number of mound visits for each team to six per nine innings.
The Detroit Tigers modified the Olde English 'D' on the home jersey to match the 'D' on the cap.
[126] The Washington Nationals added a second navy blue jersey to commemorate the team's hosting of the 2018 All-Star Game.
[127] Both the Cincinnati Reds and the Pittsburgh Pirates replaced their camouflage uniforms with new white alternate jerseys featuring olive and military green logos, letters and numbers.
[128][129] The following teams will wear commemorative patches for special occasions:[citation needed] As is the custom for the reigning World Series champions, the Astros wore gold-lettered uniforms at their home opener April 2 and 3.
[136] All US-based teams wore Stars and Stripes caps and uniforms from July 2–4, ending with Independence Day.
Teams wore caps denoting what league they play for (there were nine interleague series during the time period).
The event was held August 24 to 26, again coinciding with the final weekend of the Little League World Series.
The Orioles wore Braille uniforms September 18 to mark the 40th anniversary of the National Federation of the Blind's headquarters moving to Baltimore.
[145] The Braves wore 1974 throwbacks June 22 and 23 to celebrate Hank Aaron Heritage Weekend.
[146] The Mariners marked the 20th anniversary of their 1998 "Turn Ahead the Clock" promotion by wearing the uniforms from that game June 30 against Kansas City.
The Tigers wore their 1968 road uniforms September 8 at home to mark the 50th anniversary of their winning the 1968 World Series title.
On September 6, Fox Sports Detroit suspended Detroit Tigers play-by-play announcer Mario Impemba and color commentator Rod Allen for the remainder of the season after an alleged physical altercation that occurred on September 4, in which Allen reportedly placed Impemba in a choke hold at Chicago's Guaranteed Rate Field after a game they called between the Tigers and the Chicago White Sox, a claim Allen's agent has denied.
It was later announced that Impemba and Allen's contracts were not renewed for future seasons, ending their 17 years together as broadcast partners.