Sonne began his major junior career with the Calgary Hitmen of the WHL in 2004–05, playing in six games as a 15-year-old. After a 21-point rookie campaign in 2005–06, he scored 21 goals the next season and was subsequently drafted 85th overall in the 2007 NHL Entry Draft by the St. Louis Blues. A strong start in the 2007–08 season was derailed when he suffered a broken ankle in November 2007 that caused him to miss the majority of the regular season.[1] He emerged as a top player in the WHL, finishing third in league scoring in 2008–09 with 100 points 62 games.[2] He was named to the WHL East First All-Star Team, along with teammates Paul Postma and Brandon Kozun,[3] and won the Four Broncos Memorial Trophy as WHL player of the year, beating out Western Conference nominee and Bob Clarke Trophy-winner Casey Pierro-Zabotel of the Vancouver Giants.[4]
Sonne's dedication to improving his overall game as well as his leadership abilities earned him a spot with the Canadian junior team at the 2009 World Junior Ice Hockey Championships.[1] He recorded one goal and two assists in six games, as Canada won its fifth consecutive gold medal at the tournament.[5]
On April 9, 2013, Sonne was traded from the Texas Stars to the Peoria Rivermen for defenseman Carl Sneep.[6][7] Both players are considered to be loaned and remain property of their respective clubs.[8]
After four seasons within the Blues organization, Sonne was released as a free agent and signed a one-year contract with Austrian club Dornbirner EC of the EBEL on July 30, 2013.[9]