Julio Daniel Martinez (born August 21, 1987) is an American former professional baseball outfielder and designated hitter. He played in Major League Baseball (MLB) for the Houston Astros, Detroit Tigers, Arizona Diamondbacks, Boston Red Sox, Los Angeles Dodgers, and New York Mets. He made his MLB debut in 2011. A right-handed thrower and batter, Martinez stands tall and weighs .

Martinez played college baseball at Nova Southeastern University (NSU) and was selected by the Astros in the 20th round of the 2009 MLB draft. He is the first player drafted from NSU to play in the major leagues. He is a six-time MLB All-Star selection and a three-time Silver Slugger Award winner, as well as the only player to earn the latter honor twice in the same season.

On September 4, 2017, Martinez became the 18th player in MLB history to hit four home runs in a single game, doing so versus the Los Angeles Dodgers. During the Red Sox' 2018 World Series run, he won the American League (AL) Hank Aaron Award as the league's top offensive performer, leading the league in RBI, while placing second in batting average and home runs. He also won the 2018 Players Choice Award for Player of the Year.

Playing career Amateur career Martinez attended Flanagan High School in Pembroke Pines, Florida, and graduated in 2006. The Minnesota Twins selected Martinez in the 36th round, with the 1,086th overall selection, of the 2006 Major League Baseball draft, but he did not sign with the Twins.

Instead, Martinez attended Nova Southeastern University (NSU), where he played college baseball for the Sharks from 2007 through 2009. He set the school's career record for home runs with 32, ranked second in batting average (.394), third in runs batted in (RBIs, 142), and fourth in slugging percentage (.691). In 2009, he batted .428 with 15 home runs and set a program record with 73 runs scored. He was a two-time All-Sunshine State Conference baseball player.

In 2014, Martinez was inducted into the NSU Sharks Hall of Fame.

Houston Astros Draft and minor leagues The Houston Astros selected Martinez in the 20th round of the 2009 Major League Baseball draft with the 611th overall selection. He was signed by Greg Brown, who later became the head coach at NSU. Martinez started his professional career with the Greeneville 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 RBIs, 42 bases on balls, and 55 strikeouts. He was named a Texas League All-Star.

2011 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.

2012 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 RBIs in 2012.

2013 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 studying 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 had just made the All-Star team and was on pace to triple his home run output, and realized, "Castro's got the same swing they do." Martinez asked Castro how he had learned his technique, to which he replied, "You've got to see my guys in California." The day after the season ended, Martinez was in Santa Clarita for an appointment with hitting experts Robert Van Scoyoc and Craig Wallenbrock.

After two weeks in Santa Clarita, Martinez traveled to play for the Leones del Caracas in the Venezuelan Professional Baseball League. In one month, he batted .312 with six home runs and a .957 OPS. Of greater import was the response of the ball each time he hit it: there was a feeling of newfound mastery. However eager Martinez was to demonstrate this increased prowess to general manager Jeff Luhnow and manager Bo Porter, they remained unconvinced. He played sparingly the following spring training, receiving 18 total at bats and collecting three hits. The Astros outrighted Martinez off the major league roster on November 20, 2013, and released him on March 22, 2014. After three years and 252 games in an Astro uniform, Martinez had hit .251 with 24 home runs.

Detroit Tigers 2014

On March 24, 2014, the Detroit Tigers signed Martinez to a minor-league contract. After hitting 10 home runs and driving in 22 runs over his first 17 games with the Triple-A Toledo Mud Hens, the Tigers purchased Martinez' contract, and recalled him to the roster to play his first game on April 21.

Martinez was awarded the American League (AL) Player of the Week Award for the period ending June 22, 2014. He batted .444 (12-for-27) with three doubles, four home runs (including one grand slam), 11 RBIs, and six runs scored in seven games to win his first career weekly honor. Martinez was named the Detroit Tigers' Player of the Month for June, posting a .345 average with nine doubles, seven home runs and 21 RBIs, including a career-high 14 game hit streak. He tied for third place in the American League in home runs.

Martinez authored a breakout regular season in 2014, finishing with 30 doubles, 23 home runs, 76 RBIs, .315 batting average, and a .912 OPS, all career-highs to that point in his major league career. He was second on the club in batting, slugging percentage (.553), and OPS, and third in home runs. He was named a finalist for the MLBPA's Players Choice Award for AL Comeback Player of the Year.

On October 3, during Game 2 of the American League Division Series (ALDS) against the Baltimore Orioles, Martinez became the first player in Tigers history—and just the 16th major leaguer—to hit a home run in each of his first two career postseason games. Martinez finished the postseason with one double, two home runs, and five RBIs in three games as the Tigers were swept by the Orioles.

2015 On January 16, 2015, Martinez and the Tigers avoided arbitration when the two parties agreed on a one-year, $3 million contract for the 2015 season. On June 21, Martinez hit three home runs and had six RBIs in a game against the New York Yankees, becoming the first Tigers player to do so since Miguel Cabrera did it in May 2013. Martinez was awarded the AL Player of the Week award for the period ending July 5. He batted .458 (11 for 24) with six runs scored, four home runs, one double, and 10 RBIs in six games to win his second career weekly honor. He paced the Majors in slugging percentage (1.000) and total bases (24) and finished tied for first in home runs. Among AL leaders, he finished tied for first in on-base percentage (.500), second in RBIs, third in batting average, tied for third in hits, and tied for fourth in runs scored. On July 6, 2015, Martinez was named as a reserve for the American League at the 2015 All-Star Game.

Martinez finished the season with a .282 batting average and reached career highs of 33 doubles, 38 home runs, and 102 RBIs. His 38 home runs marked the third-highest total by a Tigers outfielder, trailing only Rocky Colavito's 45 in 1961 and Hank Greenberg's 41 in 1940. Martinez's 102 RBIs marked the most by a Tiger outfielder since Magglio Ordóñez drove in 103 in 2008. Martinez's 319 total bases ranked fifth among all AL hitters. His 109 runs created ranked eighth, and his .897 OPS ranked ninth. He had the highest percentage of hard-hit batted balls in the majors (42.8%). Following the 2015 season, Martinez was awarded his first career Silver Slugger Award. He was named the 2015 Tiger of the Year by the Detroit chapter of the Baseball Writers' Association of America.

Martinez was also a finalist for his first Gold Glove Award in right field, but the award went to Kole Calhoun of the Angels. Martinez' 15 outfield assists tied for third in the AL, his .993 fielding percentage led all AL right fielders, and his 7.7 ultimate zone rating ranked second among AL right fielders.

2016

On February 8, 2016, the Tigers signed Martinez to a two-year, $18.5 million contract extension.

Martinez was placed on the 15-day disabled list after a June 16 game against the Kansas City Royals, having suffered a non-displaced fracture in his right elbow caused by running into the outfield wall. At the time of the injury, Martinez was hitting .286 with 12 home runs and 39 RBIs.

On August 3 against the Chicago White Sox, in his first game after being activated from the disabled list, Martinez hit a pinch-hit game-winning solo home run off Chris Sale on the first pitch of the at-bat. Martinez played 120 games in the injury-shortened 2016 season and hit .307 with 22 home runs and 68 RBI.

2017 During a spring training game on March 18, 2017, Martinez left the game with an apparent foot injury. One week later, on March 25, further tests revealed that there was a lisfranc sprain in his right foot. As a result, Martinez began the season on the 10-day disabled list, with 3–4 weeks to recover. He rejoined the Tigers on May 12 after a four–game rehab stint with Toledo.

Martinez was awarded the AL Player of the Week award for the period ending May 21. Martinez batted .389 (7 for 18) with seven runs scored, four home runs, and nine RBIs while reaching base 17 times in six games to win his third career weekly honor. Next, Martinez was awarded the AL Player of the Week award for the period ending July 16. Martinez batted .454 (5 for 11), with two runs scored, two home runs, and seven RBIs in three games to win his fourth career weekly honor. During the 2017 season with the Tigers, Martinez batted .305 with 16 home runs, 39 RBIs, and a 1.018 OPS. Over four seasons with the Tigers, he hit .300 with 99 home runs, 285 RBIs, and a .912 OPS.

Arizona Diamondbacks On July 18, 2017, the Tigers traded Martinez to the Arizona Diamondbacks for Dawel Lugo, Sergio Alcántara, and Jose King.