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. Mil reached the height of at age 12, and grew to by 14 and 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.
Van Mil signed a seven-year deal as a non-drafted free agent on 7 July 2005, with the Minnesota Twins. Van Mil threw scoreless innings for HCAW in 2006, spending most of the year with the Gulf Coast League Twins of the Rookie-levelGulf Coast League. Van Mil pitched for the Beloit Snappers of the Class AMidwest 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 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-AdvancedFlorida State League. Later that year, he was promoted to the New Britain Rock Cats in the Class AAEastern 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 20 November 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 27 August 2010.
On 5 May 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 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.
Curaçao Neptunus
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.
Return to the Minnesota Twins
Van Mil pitched for the Minnesota Twins AAA affiliate, the Rochester Red Wings, on 2 September 2015, pitching 2 scoreless innings in relief in his first action stateside since 2013. 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's Northern Division. The 7-foot-1 Dutch native had allowed 15 runs in 5 1/3 innings over his first five appearances with Triple-A Rochester. On 25 April 2016, he was released by the Minnesota Twins.
Van Mil threw a fastball that averaged, which had been recorded as fast as. Van Mil also threw a slider and a change-up. Van Mil was and weighed. He was one of the tallest players in the history of professional baseball, tied with former Major League Baseball prospect Ryan Doherty.
Death
On 29 July 2019, the Dutch national baseball team announced that van Mil had died. Not much information was immediately given on what had happened. It was later revealed that he had died as a result of head injuries sustained from a hiking accident the previous December.