That doesn't seem to be Rivera's style, but as Robertson went on to say, stranger things have happened in sports. Yankees manager Joe Girardi said that he read Rivera's comments, but hasn't heard anything official from Rivera himself.
"Obviously we all knew that one day it's going to come to an end," Girardi said. "Do I necessarily feel in my mind that this is going to be his last year? No, I don't. So I don't know if I look at it that way."
Rivera said that he has only told his family so far about a decision he reached two or three weeks ago; the Yankees will be the next to know, and then Rivera promised to let the rest of the world in on the secret.
There is a certain allure to going out on top. Rivera may have lost a few miles per hour from his offerings in recent years, but it hasn't affected his performance.
The all-time saves leader with 603, Rivera had a 1.91 ERA and 44 saves last season in 49 chances, and he was perfect in save opportunities at Yankee Stadium.
"Those are big shoes," Robertson said. "Those are shoes that I don't think anybody's ever going to really be able to fill."
Robertson said that at some point, he would like to have the opportunity to serve as a closer at the Major League level. Rafael Soriano, whom the Yankees signed to a three-year, $35 million deal last year, led the American League with 45 saves in 2010 for the Rays.
While Girardi said that he believes both pitchers could theoretically step into the closer's role after Rivera, no one wants to nudge Rivera toward the door.
"I'm not really 100 percent on if he's going to retire or not," Soriano said. "To me, I look forward to helping the team. Whatever decision he makes, it's fine with me. We'll see what happens. I'm not going to think about that; I think about winning this year."
With Rivera unavailable last Sept. 3 against the Blue Jays, Robertson stepped in and was able to nail down his only save of the year in a two-inning outing at Yankee Stadium.
Robertson recalled being drained by the appearance, and said he prefers having Rivera standing by as backup.
"It's great, especially when you're struggling and you can only get two guys out and you're leaving runners stranded," Robertson said. "But you've got Mo, the best in the game, coming in behind you."
That excellence was why Rivera continues to be granted certain special privileges during Spring Training.
Last month, Rivera told general manager Brian Cashman that he would be late reporting to camp, and Cashman didn't hesitate to allow Rivera as much leeway as he needs.
Rivera also saves the Yankees from issuing a pair of gray pants every spring, as the team doesn't subject him to going on road trips for Grapefruit League games.
"Every year, he knows what he needs to do," Cashman said. "He gets his eight innings in the spring, but he's just amazing. He really is amazing. You'll never see anything like that again."
That's why the Yankees hope that Rivera takes as much time as he needs, as no one -- save for perhaps the rest of the AL -- is looking forward to a day when No. 42 isn't waiting in the bullpen.
"When Mo comes in the game, you really feel that it's over," Girardi said. "We know that's not going to happen 100 percent of the time, but over the years when Mariano came in, you felt really good about your chances. That's not always the case with every closer. I don't think we've ever really worried about Mo."
Just in case the end is indeed near, it might be a good idea to watch Rivera's graceful, flawless form a little more closely this year. There will be a day, probably in the near future, when someone else is called upon to be the Yankees' closer.
No matter who gets the call, it will be an unenviable, impossible position.
"You've just got to hope you can step in there and hold your ground; do as best you can and hope for the best," Robertson said. "You're talking about replacing a guy like Mariano Rivera. That's something I don't know if it can ever be done. I just don't think so."