He played high school football under head coach Thomas Wilcher at Cass Technical High School in Detroit. While in high school, the 6 foot, 5 inch defensive tackle was also the team's punter and kicker and ran the 40-yard dash in 4.9 seconds.[1] He played in the U.S. Army All-American Bowl, was selected as a first-team All-American by Parade magazine, EA Sports, and SuperPrep magazine. He was ranked as the best high school player in Michigan, the best defensive player in the Midwest, and one of the top high school players in the United States.[1][2] Campbell had numerous scholarships offers and eventually narrowed his choice to Miami, LSU, and Michigan.[2]
He had committed to play for Michigan while Lloyd Carr was head coach, but reopened his recruiting in September 2008 after Rich Rodriguez took over as the head coach.[2] In January 2009, on the sidelines of the Army All-American Bowl, Campbell committed to Michigan.[3]
2009 season
Campbell enrolled early at Michigan in January 2009 and participated in the Michigan football team's spring practice.[2] During the 2009 season, Campbell appeared as a true freshman in all 12 games on special teams and played in nine games as a defensive tackle.[1]
2010 season
Midway through the 2010 season, head coach Rich Rodriguez assigned Campbell to the offensive line. He also appeared as a fullback in goal line situations. He appeared in all 13 games for Michigan and received his second varsity letter.[1]
2011 season
When new head coach Brady Hoke took over in January 2011, Campbell met with Hoke and asked to return to the defense.[4] In March 2011, Hoke announced that Campbell was returning to the defense.[5] Campbell appeared in all 13 games for the 2011 Michigan team. He recovered a fumble in Michigan's come-from-behind victory over Notre Dame in the first night game ever played at Michigan Stadium.[1] After a disappointing showing in his first two seasons,[6] Campbell won praise in the press for his improved play in 2011.[7]
2012 season
In late May 2012, Campbell was charged with felony malicious-destruction-of-property arising out of an incident on April 7 in which the 322-pound athlete "slid across the hood" of a Lincoln Town Car, causing damage to the hood.[8][9][10] He reached a plea deal in June 2012 in which the felony charge was waived in exchange for a guilty plea to a misdemeanor charge and an agreement to pay $2,100 in restitution to the vehicle's owner.[10][11][12]
In August 2012, Campbell showed up at training camp having lost 46 pounds.[13][14][15][16][17][18][19] A writer for an Ann Arbor newspaper reported:
Overweight and out of shape for most of his career, Campbell generally spent the first week of Michigan football practice catching his breath and figuring out how he'd make it through the first month of the season. Not this time, though. 'I'm not huffing and puffing anymore,' the senior defensive tackle said after practice Monday. 'I'm not dying right now.'[13]
Teammate Taylor Lewan added, "His conditioning shows it. You should seem [sic] him run – it's like a gazelle. Unreal."[20] Team captain Denard Robinson joked: "Will shows off his stomach more than I do. You can tell that he lost that weight."[21]
Campbell was a starter at defensive tackle for the 2012 Michigan Wolverines football team.[22] He appeared in all of Michigan's first nine games. He totaled a career-high five tackles and had an unassisted sack in the season opener against Alabama. He has appeared in 47 consecutive games for Michigan.[1] He was a 2012 All-Big Ten honorable mention selection by the media for the 2012 Wolverines.[23][24]
Campbell was signed to the Green Bay Packers' practice squad on January 5, 2016.[30] On January 18, 2016, he was re-signed by the Packers after the season ended.[31] Campbell was released on May 9, 2016.[32]
Tennessee Titans
Campbell was signed by the Titans. On August 28, 2016, Campbell was waived by the Titans.[33]
Campbell was traded to the Seattle Dragons along with wide receiver Alonzo Moore in exchange for defensive tackle Shane Bowman on January 19, 2020.[35] Campbell was waived on March 11, 2020.[36]