2011-12: Fredrik Olofsson skated in four games for the Colorado Thunderbirds U16 team along with his older brother Gustav Olofsson (MIN) and was one of the top scorers for the club’s bantam AAA team. In four U16 games he scored 2 goals with 1 assist. He was selected by the Green Bay Gamblers in the fifth round (74th overall) of the 2012 USHL Futures Draft.
1212-13: Olofsson appeared in eight games with the USHL Green Bay Gamblers as a 16-year-old; spending most of the year with the Colorado Thunderbirds U16 team. In November he committed to playing college hockey at Colorado College in 2015-16. He had no points nor penalties and was minus-2 in limited ice time with the Gamblers. Olofsson was the Thunderbirds’ second-leading scorer behind Michael Eyssimont — scoring 26 goals with 43 assists and 8 penalty minutes in 31 games.
2013-14: Olofsson began his first USHL season with Green Bay after skating for his native Sweden in the 2013 Ivan Hlinka Memorial Tournament. In January he was obtained by the Chicago Steel in exchange for forward Patrick Polino in a trade. Olofsson scored 2 goals with 4 assists and was minus-6 with 21 penalty minutes in 24 games with the Gamblers and in 24 games with Chicago scored 4 goals with 11 assists and was minus-2 with 24 penalty minutes. Chicago missed the playoffs after finishing seventh in the Eastern Conference. Not among the 210 North American skaters in the Central Scouting final rankings Olofsson was selected by Chicago in the fourth round (98th overall) of the 2014 NHL Draft.