"Kevin is a well-respected, experienced hitting coach," Hart said. "He was a great player and as a coach he has a skill set that will benefit our club. Jose brings a tremendous resume in the hitting discipline. He has been a coordinator and hitting coach for many years and he has a long-standing relationship with Fredi."
Added Gonzalez: "We made two very good additions to our Major League staff today with Kevin and Jose. We interviewed some great candidates and we are excited to have our staff in place."
Seitzer, 52, spent the 2014 season as the hitting coach for the Toronto Blue Jays. He also previously served as the hitting coach for the Kansas City Royals for four seasons (2009-12) and the Arizona Diamondbacks (2007).
Under Seitzer's guidance, the 2014 Blue Jays ranked fourth in the American League in runs scored and ranked third in home runs. While with Kansas City, Seitzer helped the 2010 Royals post a .274 batting average, which ranked second in Major League Baseball, while the 2011 Royals squad ranked fourth with a .275 mark.
A native of Springfield, Ill., Seitzer enjoyed a 12-year Major League career, with a lifetime batting average of .295 for the Royals (1986-91), Milwaukee Brewers (1992, '93-96), Oakland Athletics (1993) and Cleveland Indians (1996-97).
Castro, 56, spent the 2014 season as the quality assurance coach for the Chicago Cubs and has more than 25 years' experience as a minor league hitting coordinator or hitting coach in the Montreal, Florida, San Diego and Seattle organizations. Castro was Seattle's interim major league hitting coach in 2008.
Castro began his coaching career in 1990 with Montreal, handling hitting coach duties at Single-A Jamestown. From 1992 to 2001, he was a minor league hitting coach in the Florida Marlins system, before returning to Montreal in 2002-03. He worked in the San Diego Padres system from 2003 to 2007 and was with Seattle as the minor league hitting coordinator from 2008 to 2010 (serving as interim major league hitting coach for the second half of the '08 season).
A former infielder, Castro was selected by Philadelphia in the 27th round of the 1977 June draft and batted .275 during his 14-year minor league career, which saw him ascend as high as Triple-A in stints with the Phillies, Chicago White Sox, Toronto Blue Jays, Kansas City Royals and Expos.