Updated

Mariano Rivera admitted the unthinkable had been a possibility.

The Boston Red Sox offered him a chance to turn in his pinstripes and switch sides in baseball's fiercest rivalry.

"It was real. It was real," he said Thursday.

While Boston made an offer to the great closer, Rivera accepted a $30 million, two-year contract from the Yankees, the only major league team he's ever played for.

He was back at Yankee Stadium, two days after finalizing his deal, to assist with the team's holiday food drive, in which fans could exchange 30 pounds of food for two tickets to select games next year.