He scored at a point-per-game pace with Manitoba, registering 15 goals and 37 assists in 52 games. He was recalled to the Jets on two occasions finishing with 2 goals in 15 games. On August 1, 2018, following the completion of his entry-level contract earlier in the off-season, Petan was signed as a restricted free agent to a one-year, two-way extension with the Jets. Petan, now waiver eligible, began the 2018–19 season with the Jets. He played sparingly for the Central Division-contending Jets, appearing in just 13 games approaching the trade deadline before he was traded to the Toronto Maple Leafs in exchange for Pär Lindholm on February 25, 2019. On March 21, Petan signed a two year contract extension with the Leafs. At the 2012 Ivan Hlinka Memorial Tournament, Petan helped Canada's under-18 team win the gold medal. During the 2013–14 season, he represented the WHL in the Subway Series, then played for Canada's under-20 team at the 2014 World Junior Ice Hockey Championships. He was invited back to represent Canada at the 2015 World Junior Ice Hockey Championships, where he was instrumental in Canada's gold medal win, including scoring a hat-trick against Slovakia in the semi-final.