In the 1991 season, Thomsen became the only TCU player in program history to hit for a home run cycle in a March 1, 1991, doubleheader against Northeast Louisiana (now UL Monroe).
He earned a Bachelor of Science in criminal justice from TCU in December 1993 and received his master's in secondary education from ACU in 2000.
In 1999, Thomsen left ACU to go into private business, but eventually returned to coaching as he became offensive coordinator at Wichita Falls High School in 2001.
Following his tenure at Wichita Falls High School, Thomsen served a two-year stint as offensive line coach at the University of Central Arkansas.
[1] In December 2008, Thomsen applied for the vacant head coaching position at Northwestern State University and was named among the six finalists.
After the 2016 season Thomsen departed Arizona State to become the offensive line coach at Texas Christian University under Gary Patterson.
[10] Thomsen served as acting head coach for a single game after Norvell tested positive for the coronavirus.