Van Mil has also pitched for the Netherlands national baseball team. Most notably, he served as the team's closer in the 2013 World Baseball Classic and the 2015 Premier 12. Additionally, he appeared in the 2007 Baseball World Cup. Though he was selected to appear in the 2008 Summer Olympics, he missed the tournament due to injury.
Van Mil competed in judo from ages 4 through 7. When his mother encouraged him to join a team sport, he chose to play baseball, as he had played a similar game in his elementary school.
Van Mil reached the height of 1.85 m (6 ft 1 in) at age 12, and grew to 2.01 m (6 ft 7 in) by 14 and 2.13 m (7 ft 0 in) at the age of 15. He played as a catcher, until he became too tall to play the position and shifted to first base. At the age of 17, a coach decided to try Van Mil as a pitcher due to his strong throwing arm.
In 2005, at age 20, Van Mil debuted with Honkbalclub Allen Weerbaar (HCAW), a Dutch professional baseball team from Bussum. He pitched to a 2–3 win–loss record with a 5.26 earned run average (ERA) and 34 strike outs, allowing 59 hits and 24 walks in 51 1⁄3 innings pitched.
Van Mil signed a seven-year deal as a non-drafted free agent on July 7, 2005 with the Minnesota Twins. Van Mil threw 1 2⁄3 scoreless innings for HCAW in 2006, spending most of the year with the Gulf Coast League Twins of the Rookie-level Gulf Coast League. He had a 1–2 record, with a 3.30 ERA in 10 games, eight of them starts.
In 2007, the right-hander had a 2–2 record, with a 2.63 ERA in 13 relief stints for the Elizabethton Twins of the Rookie-level Appalachian League and held opponents to a .171 average, though he walked 17 batters in 24 innings. He struck out 23 batters.
Van Mil pitched for the Beloit Snappers of the Class A Midwest League during the 2008 season. He had a 2–2 record with 3 saves and a 3.22 ERA and 42 strikeouts in his first 44 2⁄3 innings, making the Midwest League All-Star game. Van Mil suffered a partially torn ulnar collateral ligament in his right arm while preparing for participation in the 2008 Summer Olympics, and missed the first seven weeks of the 2009 season while rehabilitating.
Van Mil began his 2009 season in late May with the Fort Myers Miracle, playing in the Class A-Advanced Florida State League. Later that year, he was promoted to the New Britain Rock Cats in the Class AA Eastern League. He finished the season with a 1–1 record and a 2.79 ERA in 42 games between the two clubs, 25 games out of the bullpen with Fort Myers with a 2.86 ERA and another 8 games with New Britain for a 2.45 ERA. On November 20, 2009, he was added to the Twins' 40 man roster.
Van Mil began the 2010 season with Fort Myers. He was designated for assignment to make room on the roster for Brian Fuentes on August 27, 2010.
Van Mil was announced as the player to be named later going to the Los Angeles Angels of Anaheim in the trade for Fuentes on September 1, 2010.
With the Arkansas Travelers of the Class AA Texas League in 2011, Van Mil had a 3–5 record and 2.04 ERA in 66 1⁄3 innings across 30 games. He began the 2012 season with the Class AAA Salt Lake Bees, where he had a 1–0 record and 6.30 ERA. He allowed ten runs, seven of them earned, in ten innings.
On May 5, 2012, the Angels traded Van Mil to the Cleveland Indians for future considerations. The Indians assigned him to the Akron Aeros of the Class AA Eastern League.
Van Mil signed a minor league contract with the Cincinnati Reds on December 21, 2012.
In 2013, he spent most of the 2013 season in AA.
Van Mil signed a one-year deal with the Rakuten Golden Eagles of Nippon Professional Baseball in early 2014. He spent most of the year with Rakuten's farm team.
In March 2015 it was announced that van Mil would spend the year with Curaçao Neptunus Rotterdam of Honkbal Hoofdklasse. Van Mil was also named to Team Europe's roster for the 2015 Global Baseball Matchup against Samurai Japan.
On August 5, 2015, he re-signing with the Minnesota Twins who first signed him as a free agent back in 2005. Van Mil pitched for the Minnesota Twins AAA affiliate, the Rochester Red Wings, on September 2, 2015, pitching 2 scoreless innings in relief in his first action stateside since 2013. He last pitched in the United States with the Cincinnati Reds AAA affiliate Louisville. Both the Rochester Red Wings and the Louisville Bats play in the International League. However, on 10 April 2016, Van Mil in relief gave up four runs in 1.2 innings with a strikeout against Pawtucket, 4 – 9. With the loss, the Red Wings went to 4–8 on the season, the team losing six of their last eight games. They dropped to last place in the International League North.
The 7-foot-1 Netherlands native had allowed 15 runs (14 earned) in 5 1/3 innings over his first five appearances (including one start) with Triple-A Rochester. On 25 April 2016, he was released by the Minnesota Twins. As expected, van Mil returned to his home country in the Netherlands, and offered himself to Curaçao Neptunus again.
His abandonment of his major league dream seemed to be confirmed by his success as a pitcher since his return (at odds with his poor performance for the Red Wings), due to his desire to travel less and concentrate on being a family man.
After he was released, he returned to Curaçao Neptunus, the professional Dutch team from Rotterdam. Curaçao Neptunus participated in the European Championship Cup in Rimini, Italy from 31 May to 4 June 2016, coming in fourth.
Van Mil pitched relief for Curaçao Neptunus in the 2016 Holland Series. Neptunus won their fourth consecutive title in the best-of-seven series in October 2016.
Van Mil signed with the Adelaide Bite of the Australian Baseball League for the 2016 season.
Van Mil joined the Netherlands national baseball team for the first time for the 2007 Baseball World Cup. He pitched 2 1⁄3 perfect innings in a save against the Venezuela national team and threw three shutout innings for a save against the South Korea national team to keep the Dutch hopes alive for the quarterfinals; they advanced after they upset Cuba the next game. Van Mil threw 3 2⁄3 scoreless frames against the host Chinese Taipei national team in the quarterfinals to help the Netherlands win again. Van Mil pitched 1 1⁄3 scoreless innings in the Bronze Medal game against the Japan national team but was removed from the game after a walk to open the eighth inning and the runner came around to score. Van Mil still finished the Cup with a 0.71 ERA, second to Kenny Berkenbosch on the fourth-place Dutch team. He led the Netherlands with two saves.
Robert Eenhoorn, coach for the Dutch team, selected Van Mil for the Dutch team competing in the 2008 Summer Olympics in Beijing. However, he returned home before the games started due to a partially torn ulnar collateral ligament in his right elbow. Van Mil was replaced by veteran Dave Draijer. This injury also prevented him from representing his country in the 2009 World Baseball Classic.
Van Mil competed for the Kingdom of the Netherlands national team in Senart, France from August 31 to September 4, 2016 in the France International Baseball Tournament (Yoshida Challenge). The Netherlands won all four games, winning the tournament. From 13 September to 18 September 2016, the KNBSB competed in the European Baseball Championship. The Dutch team won all games, against European countries Great Britain, Germany, Russia, Czech Republic, Sweden, Spain, and Italy. Van Mil was the closer in the thrilling final championship game against Spain in Hoofddorp, Netherlands. Spain tied the game in the eighth, but the Netherlands prevailed after all, scoring the game-winner in the tenth on a walk-off single; final score 3–2.
He is competing as part of the KNB team in the 2017 World Baseball Classic in March 2017. In what NBC reported was thought to be the tallest batter-pitcher matchup in baseball history, the 7-foot-1-inch (2.16 m) van Mil walked 6-foot-8-inch (2.03 m) Nate Freiman of Team Israel at the 2017 World Baseball Classic in a round one game.
Van Mil throws a fastball that averages 95 miles per hour (153 km/h), which has been recorded as fast as 99 miles per hour (159 km/h). Van Mil also throws a slider and a change-up.
Van Mil is 7 feet 1 inch (2.16 m) and weighs 240 pounds (110 kg). Van Mil is the tallest player in professional baseball.