TAMPA, Fla. — In carving out a career as baseball’s greatest closer, Mariano Rivera never relied on deception to amass a record 603 saves. He has one remarkable pitch: everyone knows it is coming, and there is little intrigue about it.

But when it comes to matters like the timing of his retirement, Rivera is rarely as direct and assertive as he is on the mound. Instead, he is often cagey, even playful.

And so on Monday a handful of reporters were left wondering what Rivera meant when he declared that he had made an “irrevocable” decision about whether this would be his final season. Rivera refused to reveal that decision, saying he would announce it sometime later in the year, whether that is tomorrow, July or October.

But in a parsing of each sentence, and a study of the expressions on his face and the tone of his voice, it certainly sounded as if Rivera had decided that 2012, his 18th season with the Yankees, would be his last. He said he had agonized over the decision.