Joseph Anthony "Trey" Mancini III is an American former professional baseball first baseman, outfielder, and designated hitter. He played in Major League Baseball (MLB) for the Baltimore Orioles, Houston Astros, Chicago Cubs, and Los Angeles Angels from 2016 to 2026. His nickname "Boomer", originally "Boom Boom" after Ray Mancini, morphed into its current form when he enrolled at the University of Notre Dame. The Orioles selected Mancini in the eighth round of the 2013 MLB draft. He made his MLB debut in 2016 with the Orioles.