The Houston Astros and minor leaguer Jon Singleton agreed on a historic contract Monday, guaranteeing the first baseman $10 million before he has played a single game in the major leagues, a source with knowledge of the deal told Yahoo Sports. The 22-year-old Singleton, who during spring training called himself a marijuana addict, can make up to $30 million over eight seasons, the first five of which are guaranteed and the final three of which the Astros control with club options. The improved Astros, who last week won seven straight games, will call up Singleton from Triple-A Oklahoma City and install him as their everyday first baseman after more than a month of negotiations ended in a deal sure to arouse discussion around the sport. While Rays star Evan Longoria signed his first deal within days of his big league debut, the Singleton contract is the first ever long-term extension for a player with zero major league service time. The Astros’ desire to exchange up-front money for future cost certainty and Singleton’s off-field troubles brought both sides together in hopes of striking a mutually beneficial accord that was made official Monday when he passed a physical.