Background
Diem was born in Roselle, Illinois, played college football at Northern Illinois, and was drafted by the Colts in the fourth round of the 2001 NFL Draft.
Diem was born in Roselle, Illinois, played college football at Northern Illinois, and was drafted by the Colts in the fourth round of the 2001 NFL Draft.
Born in Roselle, Illinois, Diem graduated from Glenbard North High School of nearby Carol Stream in 1997.
Diem played for the Colts from 2001 to 2011 and was part of the Super Bowl XLI championship team of 2006 and Super Bowl XLIV runner-up team of 2009. Diem played defensive lineman in high school football and played on the high school track and field team An all-state selection in track, Diem set state records in both indoor and outdoor shot put as a senior.
At Northern Illinois University, Diem played for the Huskies football team for four seasons from 1997 to 2000 and majored in mechanical engineering.
As a freshman in 1997, Diem started seven games as right tackle. In his sophomore season of 1998, Diem returned as right tackle and earned second-team All-MAC honors.
Based on Diem"s combine workout results alone, Pro Football Weekly predicted that Diem would be a first-round draft pick but considered him "an average athlete with limitations." Diem was drafted by the Indianapolis Colts in the fourth round of the 2001 NFL Draft. He played his entire career for the team, starting 150 of 158 games at offensive tackle and guard from 2001 to 2011.
He retired on March 23, 2012.
He was a member of the Colts Super Bowl XLI victory over the Chicago Bears.