2014 (Redshirt) Poppen redshirted during his first year at Nebraska.
Before Nebraska Garrett Poppen joined the Nebraska program as a linebacker prospect after starting on both sides of the ball at Giltner High School. Poppen recorded more than 225 tackles in his career for Coach Jeff Ashby, including 124 tackles during his senior season. Poppen also rushed for 1,150 yards and 17 touchdowns as a senior, and caught 23 passes, including two touchdowns. He also handled kickoff duties for the Hornets. His play as a senior helped Giltner to a 9-2 record and a trip to the quarterfinals of the Class D-2 state playoffs. Poppen was also a standout performer during his junior season in 2012, helping Giltner to a perfect 13-0 record and a state championship. Poppen totaled more than 1,600 rushing yards and had 24 rushing touchdowns, while also catching 61 passes with 13 touchdowns during his career. As a senior, Poppen was a second-team All-Nebraska defensive selection by the Omaha World-Herald, while earning first-team Class D-2 all-state honors from the World-Herald and Lincoln Journal Star. Poppen earned all-district honors as both a sophomore and junior. He is the son of John and Kris Poppen, and was born on Oct. 9, 1995.