He played college football for the North Texas Mean Green and was signed by the Tennessee Titans as an undrafted free agent after the 2002 NFL draft.
In football, as a senior, he rushed for 1431 yards and 20 touchdowns and passed for 839 yards and eight touchdowns, he was named the Class 3A All-West MVP, and won All-State second-team honors.
Kassell was a four-year letterman who played in 44 games at the University of North Texas and was named Sun Belt Conference Defensive Player of the Year during his junior and senior season.
[1] In 2012, Kassell joined Catz Sports Performance and Physical Therapy in Austin, Texas, as president and partner.
[2] In 2014, he started teaching and coaching at Lago Vista High School in Lago Vista, Texas, coaching the linebacker position of the football team, powerlifting, and girls' track and field.