The Kansas City Chiefs were the youngest team in football last year, but new general manager Scott Pioli wanted to install some veteran leadership.
Vrabel was one of the leaders of the Patriots' defense, and it will be his job to teach a good work ethic to the Chiefs.
In trading Vrabel, the Patriots cleared $3.35 million in cap room.
Vrabel spent eight seasons with the Patriots, recording 638 regular-season tackles, 48 sacks and 10 interceptions.
He also was a key member of the Patriots' Super Bowl victories in 2001, 2003 and 2004, and was a mainstay of coach Bill Belichick's game plans.
Vrabel, just by stepping into the locker room, improves the Chiefs' defensive scheme. He has 55 career sacks -- which is more than Derrick Johnson, Demorrio Williams, Tamba Hali, Turk McBride and Alfonso Boone combined. The Chiefs recorded the worst pass rush in league history with just 10 sacks last season.
John Clayton covers the NFL for ESPN.com.