After spending the weekend upgrading their offense, the New England Patriots have turned their attention to fixing one of the league's worst defenses in 2011.
La Canfora: New market strategy
This is the year of the short-term contract. Jason La Canfora explains why players are not seeking lengthy deals. More ...
Castillo missed all but one game in 2011 because of a broken leg, but has been a consistent presence on the Chargers' defensive line throughout his seven-year career.