Mark-Jan Moorman was 2 for 16 in the 2004 World Junior Championship and pitched two shutout innings for the Netherlands. He debuted in the Hoofdklasse in 2005 with the Amsterdam Pirates. He hit .273/.364/.299 as a part-time outfielder and gave up 6 runs in 8 1/3 innings on the mound. Moorman batted .256/.398/.305 in 2006 for the Pioniers. He then attended the MLB European Academy.
Moorman attended Cochise College in the US. In 2009, he had a good spring, hitting a team-best .361 and posting a .430 OBP, best on the club. He made second-team All-Region for Region 1. Back in the Netherlands, he continued to put up mediocre numbers (.234/.310/.390), but was still put on their roster for the 2009 World Port Tournament. He batted only .211/.375/.211 while splitting first base duties with Jeffrey Arends in the tournament.