Matthew Stephen Sinatro (born March 22, 1960 in Hartford, Connecticut) is an American former professional baseball player, coach and scout. A catcher during his playing days, he appeared in 140 games over ten seasons in Major League Baseball (MLB) for four clubs: the Atlanta Braves (1981–84), Oakland Athletics (1987–88), Detroit Tigers (1989) and Seattle Mariners (1990–92), and had a 15-year career as an MLB coach.

Matt was selected by the Braves in the second round of the 1978 Major League Baseball Draft. He was the 27th player chosen overall. Offensive struggles (he batted only .245 during a 1,044-game minor league career) hindered Sinatro's development. He was never a regular player in the big leagues, nor did he play in more than 37 games in any MLB season. Matt only hit one home run in his career, a two-run blow off Pete Falcone of the New York Mets on August 27, 1982. The homer contributed to a 9–8 Atlanta victory in a year when the Braves prevailed over the Los Angeles Dodgers to win the National League West Division championship by a single game.

After drawing his release from the Mariners in October 1992, Sinatro was Seattle's MLB advance scout in 1993–94 before joining the big-league coaching staff of manager Lou Piniella. He would spend his entire coaching career working for Piniella as bullpen coach, first-base coach or special assistant with the Mariners, Tampa Bay Devil Rays and Chicago Cubs. In 2012, before the cheating, he served the Houston Astros as catching coordinator and advance scout.

(excerpted from Baseball Almanac, BR Bullpen & Wikipedia)