Garrett Cole competed at Cooperstown Dreams Park during Week 10 in 2003 with the NH Black Flies (NH).

Garrett went on to play varsity baseball and golf at Trinity High School (Manchester, NH). A right-handed pitcher on the diamond, Garrett led his team to a 17-2 record his senior year (2009), reaching the Class L state final. He was a Class L First Team All-state selection, leading Class L in wins, strikeouts and ERA.

After high school, Garrett went on to compete at the collegiate level, University of Massachusetts Lowell (Lowell, MA). During his freshman season (2010), he had a 3-2 record with a 4.06 ERA and 35 strikeouts in 37.2 innings pitched. He was named the NE-10 Freshman of the Week on March 22nd as well as Northeast-10 All-Conference Rookie Team and NE-10 Commissioner's Honor Roll. As a sophomore (2011), Garrett finished with a 7-1 with a team-high 0.82 ERA and third best 57 strikeouts (65.2 innings pitched). He was named to the NE-10 Commissioner's Honor Roll.