2008-09: Sorensen split the season between the first and second U18 teams in his hometown of Sodertalje. In 18 games with the Elite League team he scored 8 goals with 9 assists and 36 PMs. Competing in Allsvenskan (second division) play he scored 10 goals with 6 assists and had 62 PMs in 18 games (including playoffs).
2009-10: Sorensen skated for Sodertalje's U18 and U20 teams as a 17-year-old and played in three international matches for Sweden's U18 national team. In 27 U20 contests for Sodetalje he scored 7 goals with 10 assists and had 54 PMs. Sorensen was the third-leading scorer for the U18 team despite appearing in just 15 of 31 games; scoring 15 goals with 27 assists. His 61 PMs were fourth most on the team. Sorensen scored three goals with the national team but did not play at the world championship tournament. He was not among the 150 European skaters in Central Scouting's final rankings but was selected by the Senators in the fourth round (106th overall) of the 2010 NHL Draft.
2010-11: Sorensen made his Elitserien debut with Djurgardens in December after joining the club to compete with its U20 squad in the Super Elite league. In eight SEL games, he scored 1 goal with 1 assist and was +2 averaging 9:27 of ice-time for sixth-place Djurgardens. Sorensen skated in 31 games for the U20 team, missing time with a back injury, and scored 14 goals with 22 assists and 53 PMs. He had 3 goals and 2 PMs in four playoff games as Djurgadens won the league's bronze medal after finishing first in the North Division. Sorensen signed a two-year contract with Skelleftea in April 2011.