Fans were stunned at the news that Mariano Rivera, the greatest closer in baseball history, suffered what may be a career-ending injury during batting practice on Thursday. But Rivera was vowing to come back from the injury on Friday.

Joe Bastone, owner of the Yankee Tavern in the Bronx, said he was stunned to hear the news about the popular and beloved Bronx Bomber.  

“I was shocked how bad it was,” he said. “It’s sad that his season is over, and it’s sad if that is the way his career ends.”

Ed Heeley, a patron at the tavern, said fans are crestfallen about the injury.

“Mariano is such an intricate part of the Yankees, “ he said. “Without him, I don’t know what the fans are going to do. ... He is the missing link in Yankee Stadium. If they don’t have Mariano, they don’t have the Yankees.”

The Yankees' 12-time All-Star tore his ACL during practice in Kansas City. He was chasing a fly ball when his right knee buckled near the warning track.

During spring training, Rivera hinted that this might be his last season, but on Friday he vowed to come back.

"Write it down in big letters. I'm not going out like this," Rivera said, his almost happy-go-lucky demeanor in stark contrast to the somber mood of the previous night.

"This has me thinking," Rivera said, "I can't go down like this."

After the accident, Rivera said he went back to his hotel room, reflected on his career and made his decision not to retire. He holds outside hope of returning late this season.

"Miracles happen," Rivera said with a smile. "I'm a positive man. The only thing is that I feel sorry I let down my teammates. Besides that I'm OK."