Kiermaier attended Bishop Luers High School in Fort Wayne, Indiana, and played for the school's baseball team. Bishop Luers won the state championship in Kiermaier's senior year. After being recruited by college programs for their football teams and almost committing to attend Purdue University, Kiermaier opted to play college baseball and enrolled at Parkland College instead, where competed in the National Junior College Athletic Association. As a freshman, Parkland won the NJCAA National Championship. Kiermaier was named a NJCAA All-American in his two years at Parkland. The Tampa Bay Rays selected Kiermaier in the 31st round of the 2010 Major League Baseball draft. Purdue again offered Kiermaier a scholarship, but he decided to sign with the Rays instead of transferring to Purdue. Kiermaier spent the 2013 season in Class AA and Class AAA, and was named the best defensive player in the Rays' organization and the Most Valuable Player of the Montgomery Biscuits of the Class AA Southern League. With Montgomery, he played 97 games, batting.307 with five home runs and 28 RBI. In AAA, he played 39 games with the Durham Bulls, batting.263 with a home run and 13 RBI.
Tampa Bay Rays (2013–present)
2013
Considering him the top defensive outfielder in their organization – including the major league club and all their minor league affiliates – the Tampa Bay Rays activated Kiermaier to both the 40- and 25-man rostersfor the first time on September 30, 2013. He made his major league debut in that evening's wild card tie-breaker game – the Rays' 163rd game of the season – and played one inning against the Texas Rangers in the ninth as a defensive replacement. Rays general managerAndrew Friedman commented that the club included Kiermaier on the major league roster late that season specifically for his defense in center field. He played two innings in the 2013 American League Wild Card Game against the Cleveland Indians, which was his only postseason appearance that year. That winter, Baseball America rated him the tenth-best prospect in the Rays' minor league system.
On May 18, 2014, Kiermaier hit his first major league home run against Mike Morin of the Los Angeles Angels of Anaheim. He finished 2014 hitting.263 with 10 home runs in 108 games and was one of the finalists for the Gold Glove Award for American League right fielders.
2015
In a game at Tropicana Field against the Kansas City Royals on August 29, 2015, Kiermaier was involved in a failed but humorous attempt to rob designated hitterKendrys Morales of a home run. He hit a fly ball which appeared to be clearing the center field fence for a home run. Kiermaier leapt and momentarily perched himself upright on the top of the fence and waited to catch the ball before it landed. However, it dropped approximately in front of the fence, and Kiermaier watched it bounce as he continued to cling to the fence. The ball had deflected off one of the catwalks suspended from the roof, and, in accordance with park rules, the umpires awarded a home run to Morales. One of 15 MLB outfielders to register a throw back into the infield at or above in 2015, Kiermaier led all MLB outfielders by reaching 100 MPH nine times, while all others combined to reach that speed 27 times. Kiermaier finished the 2015 season leading all major league fielders in Defensive Runs Saved with 42, the highest number since the start of calculations of the statistic. He garnered 5.0 defensive Wins Above Replacement, fourth all-time according to Baseball-Reference.com. His overall 7.3 WAR ranked third in the American League behind Mike Trout and Josh Donaldson. Kiermaier won his first each of the Fielding Bible Award for MLB center fielders, Gold Glove Award for American League center fielders, and the American League Platinum Glove Award, awarded to the best overall defensive player in each league.
2016
Improving upon the previous season's results as a hitter, Kiermaier began the 2016 season by decreasing his strikeout rate, nearly doubling his walk rate, and increasing his power. In a 5–4 loss to the Detroit Tigers on May 21, he fractured two bones in his left hand while attempting to catch a sinking line drive off the bat of James McCann. After undergoing surgery to repair the fractures, he was medically cleared to resume limited workouts on May 27. Despite missing significant time, Kiermaier was once again one of the best defenders in all of baseball, leading all center fielders with 25 Defensive Runs Saved despite playing in almost 400 innings less than the next player on the list, Kevin Pillar. Kiermaier also paced all major leaguers with a 2.95 dWAR. Kiermaier finished the season hitting.246 with 12 home runs, a result of his increased power. He also stole 21 bases. He was awarded with his second Gold Glove Award.
2017
Prior to the 2017 season, Kiermaier signed a 6-year, $53.5 million extension with the Rays. On June 9, it was revealed that Kiermaier had suffered a hairline fracture in his right hip after sliding into first base in a previous game. He was ruled out for at least two months. On August 18th, Kiermaier returned to the lineup, batting lead off in a game against the Seattle Mariners. After a second straight injury shortened season, Kiermaier was still able to produce in the top tier of defensive players. He came in second place in Defensive Runs Saved at center field with 22, a career low, and short only of the Minnesota Twins'Byron Buxton, whom led with 24 Defensive Runs Saved, even though Kiermaier played in over 300 less innings than Buxton. Offensively, Kiermaier slashed.276/.338/.450 with 15 home runs and 16 stolen bases; all but the SBs were career highs, even though he played in a career low 98 regular season games. Kiermaier was not eligible for the Gold Glove Award because he did not reach the innings requirement for his team's first 138 games. This was the first time he was not named a finalist for the award.
2018
On April 15, Kiermaier injured his thumb on the right hand while sliding to second base and left the game. The next day, on April 16, MRIs revealed that Kiermaier's right thumb had a torn ligament, ruling him out for up to 3 months. He returned on June 19 against the Houston Astros. Kiermaier finished the 2018 season playing only in 88 games, hitting.217 with 7 home runs and 29 RBIs.
2019
In 2019, he had the best jump of all major league outfielders. He won his third Gold Glove Award, beating out Mike Trout and Jackie Bradley Jr.
Personal life
Kiermaier proposed to girlfriend Marisa Moralobo on February 11, 2017. They married on November 10, 2017, in St. Petersburg, Florida. They welcomed their first child, a son, in November 2018. Kiermaier's older brother, Dan, is a groundskeeper for the Chicago Cubs.
