Nick Martini competed at Cooperstown Dreams Park during week 1 in 2000 with the McHenry County Generals (IL). Nick's fondest memory was during the single-elimination part of the tournament. His team was the 31st seed and advanced to the quarterfinals, losing to eventual champions San Diego Stars North (CA), 12-7. The seven runs scored were the most any team had scored against the Stars all week.

Nick graduated from Prairie Ridge High School (Crystal Lake, IL). As a member of the baseball team, he was named All State, All Area, and All Conference during his senior year. He was the winning pitcher in the 2008 Illinois Class AA title game. A three-year starter for his team, Nick batted .529 as a sophomore, .435 in 69 at-bats before an injury ended his junior year, and .429 with 15 doubles, 7 home runs and 28 steals his senior year.

Nick continued his baseball career at Kansas State University (Manhattan, KS) on an athletic scholarship. As a freshman (2009), he was the starting left fielder, recorded a .336 BA, 4 home runs, and 50 RBI. He helped his team reach the NCAA Regionals and was named All Conference, a Louisville Slugger Freshman All-American and earned Honorable Mention All-Big 12 accolades. Nick finished his sophomore (2010) season leading the team offensively with a .416 BA, which included 231 AB, 49 RS, 96 H, 17 doubles, 4 triples, 4 home runs, and 59 RBI. In 2011, Nick's junior year, he batted .326 with 24 stolen bases. He set a NCAA Division I record between 2010-2011 having reach base in 93 consecutive games.

Nick did not return to Kansas State University for the 2012 season – he was drafted by the St. Louis Cardinals in 7th round of the 2011 Major League Baseball amateur draft. Shortly after signing with St. Louis, Nick went to the short-season Class-A Batavia Muckdogs (Batavia, NY). After several years in the minors, Nick signed with the Oakland Athletics as a minor-league free agent over the winter prior to the 2018 season. Nick made his major league debut with the Oakland A’s on June 6, 2018.