Sonnenberg graduated from Madonna University in 2009, where he was named Named All-WHAC first team after posting a 2.87 earned run average in 15 appearances with 10 wins on the mound. He struck out 59 hitters in 78.1 innings of work and was named Conference Pitcher/Player of the Year and team MVP.

As a junior in 2008, he was named All-WHAC honorable mention after posting a 2.51 earned run average in 11 appearances. He struck out 41 hitters in 43 innings of work while walking just 11. He threw a no-hitter against Aquinas on April 19, striking out a season best nine betters while walking one. Prior to Madonna, Sonnenberg played two seasons at Lansing Community College.

The Lansing, Mich., native played internationally in 2010 for the Morley Eagles Baseball Club of State League Baseball in Perth, Australia. Morley won the Grand Final, Minor Premiership. Sonnenberg went 15-1 with a 1.29 ERA, plus three playoff wins. He was named team MVP and Best Finals Player as well as to t he State League All-Star Team.