|Oakland Athletics – No. 59|
|Catcher / Coach|
|Born: December 14, 1972|
|April 14, 1996, for the San Francisco Giants|
|Last MLB appearance|
|June 23, 2002, for the Milwaukee Brewers|
|Runs batted in||29|
Marcus Christian Jensen (born December 14, 1972) is an American professional baseball player and coach. He played as a catcher for the San Francisco Giants, Detroit Tigers, Milwaukee Brewers, St. Louis Cardinals, Minnesota Twins, Boston Red Sox and Texas Rangers in Major League Baseball (MLB) from 1996 through 2002. After retiring as a player, Jensen coached and managed in the minor leagues. In 2015, he was the coach for the Oakland Athletics of MLB.
Jensen attended Skyline High School in Oakland, California. The San Francisco Giants of Major League Baseball (MLB) selected Jensen in the first round, with the 33rd overall selection, of the 1990 MLB Draft. He made his MLB debut in 1996. Though he was labeled the Giants' "catcher of the future", he struggled, and was traded to the Detroit Tigers in July 1997 in exchange for Brian Johnson. He played for the Milwaukee Brewers in 1998, the St. Louis Cardinals in 1999, the Minnesota Twins in 2000, the Boston Red Sox and the Texas Rangers in 2001, and the Brewers in 2002.
Jensen played for the United States national baseball team in the 1999 Pan American Games, and the 2000 Summer Olympics.
Jensen also spent time in the New York Yankees organization in 2003, the independent Golden Baseball League from 2005 to 2006.
In January 2007, Jensen retired as an active player to become a hitting coach in the Oakland Athletics organization. From 2009 through 2013, he was the manager of the Arizona Athletics of the Rookie-level Arizona League.
Jensen succeeded Todd Steverson as the Athletics' the minor league roving hitting instructor for Athletics after the 2013 season. After the 2014 season, he was named the assistant hitting coach on the Athletics' Major League roster.
Jensen's son, Marcus Proctor, was chosen by the Tampa Bay Rays in the 2009 MLB Draft.