An unknown in camp, Gay quickly became a familiar name to Patriots fans accustomed to injuries in the secondary. Gay played in 15 games with nine starts, recording two interceptions and a touchdown. With all eyes on him in the playoffs, he helped shut down the Colts’ and Steelers’ passing games, then became one of the unlikeliest Super Bowl heroes of all time with a game-high 11 tackles and a forced fumble. ‘‘I wouldn’t have even dared to dream this,’’ he said.