Valerio Lorenzo de los Santos (born October 6, 1972 in Las Matas de Farfan, San Juan, Dominican Republic) is a Major League Baseball pitcher for the Uni-President 7-Eleven Lions.
De los Santos pitched in the major leagues from 1998-2005 for the Milwaukee Brewers, Philadelphia Phillies, Toronto Blue Jays, and Florida Marlins. On July 9, 2005, pitching in the 9th inning against the Chicago Cubs, de los Santos hit Adam Greenberg directly in the back of his head with a 91 mile per hour fastball on the very first pitch of the plate appearance. "The first thing going through your mind is, 'This guy's dead,'" de los Santos said. Greenberg, suffered a mild concussion as a result of the beaning, and still suffers from positional vertigo. To present, Greenberg's major league career consists only of this single plate appearance against de los Santos.
De los Santos pitched for the Sultanes de Monterrey of the Mexican League in 2007. De los Santos signed a minor league contract with the Colorado Rockies in January 2008. After starting the year with the Triple-A Colorado Springs Sky Sox, he was called up on July 28, 2008. He was designated for assignment on August 4 and became a free agent at the end of the season.