Poppinga served as a defensive graduate assistant and intern on Mendenhall’s staff in 2009 and 2010 before taking over the outside linebacker responsibilities for the final eight games of the 2010 season.
After playing one year in the NFL, Poppinga returned to BYU for the 2009 season as the defensive intern and contributed to the team's 11-2 record and 44-20 Maaco Bowl Las Vegas victory over No. 16 Oregon State. After the team’s 1-4 start in 2010, Poppinga was asked as the defensive graduate assistant to assume the role as outside linebackers coach and helped the Cougars finish 6-2 over the remaining games, including a 52-24 win over UTEP at the New Mexico Bowl.
Poppinga was an All-Mountain West Conference linebacker and Academic All-MWC honoree at BYU under Mendenhall while helping the Cougars achieve back-to-back conference championships in 2006 and 2007. He redshirted Mendenhall’s first season as head coach in 2005 after transferring from Utah State. Poppinga helped BYU achieve Las Vegas Bowl wins over Oregon and UCLA and led the team with 113 tackles his senior season. He played in the NFL in 2008, seeing time on three teams before going to Super Bowl XLIII with the Arizona Cardinals.
A native of Evanston, Wyo., Poppinga has completed bachelor’s (2007) and master’s (2010) degrees from BYU in exercise science. He and his wife Rebekah have two daughters.
Bronco Mendenhall on hiring Poppinga: “Kelly is a bright, aggressive and skilled football coach. He has demonstrated as a player and now as a coach that he demands excellence of himself and others. Kelly did an exceptional job this past season (2010) when asked to step into the role of coaching our outside linebackers and I’m excited to have him continue in that position.”