Greg O'Halloran debuted on May 16, 1994, playing for the Florida Marlins at Joe Robbie Stadium; he played his final game on August 6, 1994, playing for the Florida Marlins at Joe Robbie Stadium.
Greg Olson debuted on June 27, 1989, playing for the Minnesota Twins at Hubert H Humphrey Metrodome; he played his final game on September 30, 1993, playing for the Atlanta Braves at Atlanta-Fulton County Stadium.
Greg Walker debuted on September 18, 1982, playing for the Chicago White Sox at Comiskey Park; he played his final game on July 1, 1990, playing for the Baltimore Orioles at Memorial Stadium.
Greg Brummett debuted on May 29, 1993 and played his final game on September 30, 1993.
Greg Burke debuted on May 16, 2009 and played his final game on September 23, 2013.
Greg Harts debuted on September 15, 1973, playing for the at ; he played his final game on September 20, 1973, playing for the at .
Greg Garrett debuted on April 24, 1970, playing for the California Angels at Anaheim Stadium; he played his final game on April 18, 1971, playing for the Cincinnati Reds at Riverfront Stadium.
Greg Gohr debuted on April 7, 1993, playing for the Detroit Tigers at Tiger Stadium; he played his final game on September 27, 1996, playing for the California Angels at Anaheim Stadium.
Greg Brummett debuted on May 29, 1993 and played his final game on September 30, 1993.
Greg Burke debuted on May 16, 2009 and played his final game on September 23, 2013.
Greg Aquino debuted on July 2, 2004 and played his final game on June 17, 2009.
Greg Bargar debuted on July 17, 1983 and played his final game on October 2, 1986.
Greg Blosser debuted on September 5, 1993 and played his final game on April 17, 1994.
Greg Bollo debuted on May 9, 1965 and played his final game on October 2, 1966.
Greg Booker debuted on September 11, 1983 and played his final game on May 26, 1990.
Greg Briley debuted on June 27, 1988 and played his final game on September 24, 1993.
Greg Brock debuted on September 1, 1982 and played his final game on June 28, 1991.
Greg Cadaret debuted on July 5, 1987 and played his final game on September 26, 1998.
Greg Colbrunn debuted on July 9, 1992 and played his final game on June 28, 2004.
Greg Erardi debuted on September 6, 1977 and played his final game on September 24, 1977.