Is This Mariano Rivera's Last Season

Many would consider Mariano Rivera the best closer in the history of baseball, and if not he is certainly on of the best ever.  With over 600 saves and really only using on pitch Mariano Rivera has proven he is as dominant as they can be.  But as he got older his production has started to decrease as with the majority of professional baseball players.  Many people have speculated that this could be his last season.  If so does Mariano Rivera go down in the books as the best closer to play the game. In my book he would, when you look at all the numbers and situations that Mariano has faced it is clear to me that while some may have come close no one has closed game as effectively as Mariano Rivera. After the first game of the season yesterday where Rivera was brought in in the ninth inning of a one run game and gave up two runs and the Yankees lost the first game of the season.  Does Mariano have more than a season or two left in him his production seems to have declined and become less consistent.  While that may be the case Mariano is still among the most effective closers in the game finishing near the top in saves each season.  I think Mariano has one or two years left before he is done but who knows when your as good as Mariano is he could be around longer.