Before taking over in St. Louis, Spagnuolo had top 10 defenses with the Giants in the 2007 and 2008 seasons. His 2007 defense led the NFL with 53 sacks and the 2008 unit was sixth in the league with 42.

In the Giants’ 2008 Super Bowl triumph over New England, their defense sacked Tom Brady five times and the Patriots, who had led the NFL with an average of 36.8 points per game, to only 14 points.

Before joining the Giants, Spagnuolo was a defensive assistant in Philadelphia from 1999-2006. He coached Pro Bowl players including Brian Dawkins and Lito Sheppard, and helped Philadelphia field a 10th-ranked defense in the 2004 season, when the Eagles made it to the Super Bowl before falling to New England.

HC is far more different than being a DC. Some people aren't made to be HC's. I truely believe that. Some people are good at one thing not 100.
Oh and the D that is going to the SB this year was one that Spags built.