2010-11: George Sorensen played for the Herning Blue Fox junior program in Denmark — appearing in one regular season game and two playoff contests with Herning's second men's team as a 15-year-old.
2011-12: Sorensen made his pro debut in Denmark's AL-Bank Ligaen, playing five games for the Blue Fox, and split the year between Herning's second team and the club's junior team. He played for Denmark's U18 team in the 2012 World Junior Championship. Sorensen had a 4.00 goals against and .864 save percentage with the Blue Fox and played five regular season contests and three playoff games for Herning in the second league. He had a 1.60 goals against as Herning finished first in the regular season and had a 1.33 goals against in the playoffs. Sorensen had Denmark's only win — a 4-3 win over Latvia in the relegation round — and finished 1-4 with a 3.91 goals against and .907 save percentage at the WJC.
2012-13: Sorensen appeared in three regular season games for Herning Blue Fox as a backup to Lubos Pisar — posting a 1.28 goals against and .960 save percentage — and played for Denmark in the 2013 D1A U20 and U18 World Junior Championship tournaments. He saw one period of action for the U20 team, stopping 15 of 16 shots, as a backup to Sebastian Feuk. Sorensen had a memorable Division 1A tournament for the U18 team, getting a gold medal after starting and winning all five games with two shutouts. He led all goalies in goals against (1.18) and save percentage (.956) and scored an empty net goal against France.
2013-14: Sorensen spent the season sharing the goaltending for Henning with Pisar — posting a league best 1.17 goals against and .948 save percentage in 16 games — and played for Denmark's U20 team in the 2013 Division 1A World Junior Championship. Blue Fox finished second in the re-named Metal Ligaen. Denmark finished first in the D1A WJC and in four games Sorensen was 4-0 with a 2.00 goals against and .928 save percentage. In his second year of draft eligibility, Sorensen was ranked 14th amongst International goaltenders in Central Scouting's mid-term rankings prior to the 2014 NHL Draft.