Mark Mercer debuted on September 1, 1981, playing for the Texas Rangers at Arlington Stadium; he played his final game on September 28, 1981, playing for the Texas Rangers at Arlington Stadium.
Jack Mercer debuted on August 2, 1910, playing for the Pittsburgh Pirates at Forbes Field; he played his final game on August 2, 1910, playing for the Pittsburgh Pirates at Forbes Field.
Jordy Mercer debuted on May 29, 2012, playing for the Pittsburgh Pirates at PNC Park; he played his final game on September 29, 2013, playing for the Pittsburgh Pirates at PNC Park.
Win Mercer debuted on April 21, 1894, playing for the Washington Senators at Boundary Field; he played his final game on September 27, 1902, playing for the Detroit Tigers at Bennett Park.
John Mercer debuted on June 25, 1912, playing for the St. Louis Cardinals at Robison Field; he played his final game on June 25, 1912, playing for the St. Louis Cardinals at Robison Field.
Mark Acre debuted on May 13, 1994 and played his final game on May 10, 1997.
Mark Bailey debuted on April 27, 1984 and played his final game on August 22, 1992.
Mark Baldwin debuted on May 2, 1887 and played his final game on September 30, 1893.
Mark Ballinger debuted on August 6, 1971 and played his final game on September 25, 1971.
Mark Belanger debuted on August 7, 1965 and played his final game on October 2, 1982.
Mark Bomback debuted on September 12, 1978 and played his final game on July 21, 1982.
Mark Bradley debuted on September 3, 1981 and played his final game on October 2, 1983.
Mark Brandenburg debuted on July 20, 1995 and played his final game on September 27, 1997.