2009-10: Bertschy appeared in four games in Switzerland's Elite Junior A league and was the leading goal scorer for SC Bern's U17 team after transferring to the club from Gotteron. He had 1 assist with SC Bern's U20 squad. In 29 Elite Novizen (U17) league games he scored 25 goals with 15 assists and had 46 penalty minutes. SC Bern advanced to the playoff semifinals after finishing third and in nine playoff games Bertschy scored 4 goals with 7 assists and had 10 penalty minutes.
2010-11: Bertschy was the third-leading scorer for the SC Bern U20 team and skated for Switzerland at the 2011 U18 World Junior Championship and U17 European Youth Olympic Festival tournaments. He was a key player for the Elite Novizen championship SC Bern U17 team during that league's playoffs. In 36 games with SC Bern U20, he scored 16 goals with 16 assists and had 34 penalty minutes. In his only Elite Junior A playoff game he was scoreless with two penalty minutes. In six games for seventh-place Switzerland at the U18 WJC he scored 1 goal and was plus-one with 12 penalty minutes and at the EYOF he scored 1 goal with 2 assists in three games. After scoring 7 goals with 4 assists in four regular season games for SC Bern's U17 team, Bertschy was the team's second-leading scorer in the playoffs behind Julian Schmutz (36 points), finishing with 8 goals and 15 assists in nine games.
2011-12: Bertschy skated for SC Bern in the Swiss A League as a 17-year-old and represented Switzerland in the 2012 U20 World Junior Championship. Playing in 31 of 50 games during the regular season for fifth-place SC Bern, he scored 8 goals with 8 assists and was plus-four with 10 penalty minutes. Bertschy played in all 17 playoff games as SC Bern reached the finals and scored 1 goal with 1 assist and was an even plus/minus with 8 penalty minutes. He was the second-leading scorer for eighth-place Switzerland at the WJC, scoring 2 goals with 2 assists and finishing an even plus/minus in six games. Ranked 35th amongst European skaters in Central Scouting's final rankings prior to the 2012 NHL Draft, Bertschy was selected by Minnesota in the sixth round (158th overall).
Will play for Bern of the Swiss League.