Hasselborg made her international debut at the 2008 European Mixed Curling Championship, playing third for Niklas Edin, winning a bronze medal. In 2009, Hasselborg played in her first World Juniors, skipping Sweden to a 6th-place finish. At the 2010 World Junior Curling Championships, Hasselborg upset the Canadian rink skipped by Rachel Homan in the final by a score of 8–3.