Yankees closer Mariano Rivera admitted on Tuesday that 2012 could be his final season. "I don't know what will happen," said the future Hall of Famer, who turns 42 Tuesday and has one year and $15 million remaining on his contract. "I have one year left. I might call it over. I will know more in spring training." Bothered for a month by a condition that has turned his voice into a raspy whisper, is awaiting a second opinion to see if he needs a surgical procedure done on his vocal chords. "Every time I talk it gets worse and worse," Rivera said. Rivera did not know what was causing the problem, but vocal chords sometimes sprout blisters or polyps that need to be removed. When it was mentioned that shaving of the vocal chords sounded like a simple procedure, Rivera smiled. "When you are talking about surgery, there is nothing simple," Rivera said.