For 2010, he was elected as a team captain by his teammates, representing special teams. After the season, he became an unrestricted free agent. He was re-signed on November 29, 2011. In Week 13 in a game against the Green Bay Packers, Blackburn recorded an interception against Aaron Rodgers in his own end. In the fourth quarter of Super Bowl XLVI, Blackburn recorded an interception against Patriots quarterback Tom Brady, the lone turnover of the game. The play was vital to winning the Super Bowl. He also had six tackles.