McMahon, 26, was originally selected by the Oakland Raiders in the sixth round of the 2005 NFL Draft out of the University of Iowa. The 6-foot-8-inch, 330-pound offensive lineman has not played in an NFL game. He spent the 2005 season as a member of the Cleveland Browns practice squad and was in training camps with the New York Jets (2006) and Jacksonville Jaguars (2007). McMahon was out of football during the 2006 and 2007 regular seasons. He was re-signed by the Jaguars as a free agent on March 5, 2008 and was released by Jacksonville on July 25, 2008.