He played college basketball for Baylor University and represents the Canadian national team.

[1] Heslip attended Nelson High School in Burlington, Ontario where he was a three-time Halton all-star honouree and team captain in 2008–09.

[3] In December 2009, he joined the Boston College Eagles men's basketball team where he participated in practice but did not play for them in 2009–10.

[4] On June 9, 2010, Heslip signed a National Letter of Intent to play for Baylor University, and subsequently sat out the 2010–11 season due to NCAA transfer regulations.

[2][6] As a junior in 2012–13, Heslip was named to the Academic All-Big 12 first team and Big 12 Commissioner's Honor Roll for both the fall 2012 and spring 2013 semesters.

[14] His 13 3-point effort was eventually matched by Tyler Harvey on February 2, 2019, but As of March 3, 2022[update] it still stood as the league record.

[16] With Igokea, he was named the 2015 Bosnian Cup Grand Final MVP after helping his team win.

[25] In 2013, Heslip was a member of the Canadian national team that competed in the World University Games, Continental Cup and FIBA Americas Championship.

[2][26] In July 2015, he was named to the Canadian national team roster for the 2015 Pan American Games,[27] where he won a silver medal.

On April 6, 2022, Heslip was introduced as the general manager of the Scarborough Shooting Stars of the CEBL.