Astros of the Rookie-level Appalachian League, where he batted .403 before earning a promotion to the Tri-City ValleyCats of the Class A-Short Season New York–Penn League. Martinez started the 2010 season with Lexington Legends of the Class A South Atlantic League (SAL) before earning a mid-season promotion to the Corpus Christi Hooks of the Class AA Texas League. He led SAL in each of batting (.362), on-base percentage (.433), and slugging percentage (.598). At the time of his promotion to the Texas League, he also led the SAL in hits, doubles, extra-base hits, runs scored and total bases. Martinez was honored as SAL Player of the Year, Most Valuable Player (MVP), and the Houston Astros' Minor League Player of the Year. Martinez started the 2011 season with Corpus Christi; over 88 games, he batted .338/.414/.552/.959, 25 doubles, 13 home runs, 72 RBI, 42 bases on balls, and 55 strikeouts. He was named a Texas League All-Star. Early major league career (2011–14) On July 30, 2011, the Astros called up Martinez to replace Hunter Pence, whom they had traded to the Philadelphia Phillies. Martinez became the first player drafted from Nova Southeastern University to debut in Major League Baseball. The following month, he drove in 28 runs, establishing an Astros rookie record for one month. On April 13, 2012, Martinez hit the first ever home run in the new Marlins Park. With a runner on in the eighth, he hit an Edward Mujica offering into the Clevelander bar beyond the left-field wall for a game-tying home run. He led the club with 55 RBI in 2012. During a batting practice session in July 2013, hitting coach John Mallee confronted Martinez about his swing: unless he changed his approach to hitting, the best-case scenario for his playing career would be to "bounce between the big leagues and the minors." As difficult as the message was for Martinez to accept at the time, he pondered Mallee's words. The next month, while in the trainer's room after spraining his left wrist, Martinez watched ESPN highlights of Milwaukee Brewers' slugger Ryan Braun batting. He realized that his swing bore no resemblance to Braun's. From there, he began to dedicate himself to study other top MLB hitters including Albert Pujols and Miguel Cabrera to investigate what improvements he could make to his swing to become a more successful hitter. He then observed teammate Jason Castro, who