General manager Brian Cashman called Rivera on Tuesday to check on the closer's future plans and was informed that no final decision has been made.
"I talked to Mariano Tuesday night, and he is not sure what he's interested in doing just yet," Cashman said. "I think in Spring Training he was intending to retire at the end of the year, so I don't think he knows what he wants to do just yet. Am I surprised by that? No."
Cashman said that the Yankees do not need an answer at this moment, and likened Rivera's situation to that of left-hander Andy Pettitte, who said that he needs about a month to decide what he wants to do next year.
Rivera's season ended on May 3 with a torn right anterior cruciate ligament, and he vowed he would pitch again in 2013.
"I am coming back. Put it down," Rivera said the day after he sustained the injury chasing a fly ball during batting practice. "Write it down in big letters. I'm not going down like this."
Rivera spent the months following surgery taking part in intense rehab, which manager Joe Girardi said seemed to be an indication of his future plans.
"From watching how he rehabbed and everything that he was going through -- [he] picked up a baseball sooner than he was supposed to and got his hand smacked a little bit -- that would tell me that Mo probably wants to play," Girardi said on Wednesday.
But Girardi, who had not spoken to Rivera since the Yankees were ousted from in the American League Championship Series, floated the possibility that Rivera might need more time to decide what his future holds.
"I think he'll sit down with his family, evaluate where he is maybe a little bit later in this process and [see] how he feels," Girardi said. "But I don't think that you push a rehab like he pushed it unless you think that you possibly have some interest in coming back."
Rivera turns 43 next month and is set to become a free agent, and it appears unlikely that the Yankees would be willing to match his $15 million salary coming off a knee injury.
However, Cashman said that if Rivera wishes to pitch, the Yankees would obviously engage in contract negotiations.
"But if you're asking me if I know if he's going to pitch or not, the answer is, I don't know," Cashman said.