Jeffrey William Datz is an American former Major League Baseball player and former third base coach for the Seattle Mariners. On November 25, 2013, it was announced that Datz will serve the Mariners as a member of the club's professional scouting staff for the 2014 season. A former catcher, Datz played in seven games for the Detroit Tigers in 1989. He was a coach with the Cleveland Indians from 2002 until the end of the 2009 season, when general manager Mark Shapiro fired the entire coaching staff. He was manager of the minor league Buffalo Bisons in 1998 and 1999. Datz led the Bisons to the league championship crown in 1998. At the 2008 Home Run Derby at Yankee Stadium, Datz pitched for Cleveland Indians center fielder Grady Sizemore. Datz served as the bench coach for the Baltimore Orioles in 2010. On November 4, 2010, Datz was hired to be third base coach for the Seattle Mariners starting with the 2011 season. Before a Mariners game against the Los Angeles Angels of Anaheim on April 27, 2013, Datz announced that he was diagnosed with an undisclosed form of cancer, and Tacoma Rainiers manager Daren Brown was promoted to substitute for Datz. 

November 28th, 1959 in Camden (Age 65)