FOXBOROUGH, Mass. — Several hours before the New England Patriots began their defense of their Super Bowl title by taking on the Pittsburgh Steelers on Thursday night, the Rolling Stones song “Gimme Shelter” blared over the stadium sound system.
It was an apt song for a team that had been under siege since it beat the Seattle Seahawks in February to capture its fourth N.F.L. championship.
For months, the football world has focused on whether Patriots quarterback Tom Brady had a role in the deflation of footballs used in the A.