After college Campbell stayed within Ohio and took a job as a graduate assistant at Bowling Green State University from 2003–2004. While at Bowling Green Scott Pioli, then the director of player personnel for the New England Patriots, offered Campbell an interview for a job at the team, but Campbell declined. Campbell returned to Mount Union for 2005–2006 as offensive coordinator; Mount Union won the Division III championship both years. Campbell then went back to Bowling Green for two years, first as offensive line coach (2007) and then as offensive line coach/run game coordinator (2008). The University of Toledo hired him as the run game coordinator for the 2009 season. This move reunited him with head coach Tim Beckman, defensive coordinator at Bowling Green during Campbell's first stint there.