And his presence in their bullpen is unlikely to be the difference-maker if the Yankees fare better in 2013.
It's also certainly not worth getting into a guessing game over whether he'll retire at the end of the season, because when the man is ready to tell us, he will. (Personally, I think he's out of here after this season.)
The point is that not even the great Mo himself could have done much better than Rafael Soriano did in the regular season last year, which was to convert 42 of the 46 save opportunities thrust in front of him after Rivera went down with a knee injury in Kansas City on May 3.
Odds are, even if Rivera had been healthy all season long, things still would have ended the way they did, because in October, when the games got real, the Yankees had no need for a closer.
Soriano made three postseason relief appearances, but when it came to save opportunities, he never even got a chance.
So it is kind of silly to think that as Rivera's comeback goes, so go the Yankees' chances of returning to, or even winning, the World Series this year.
Whatever they wind up doing, for good or ill, is probably going to have to be done at the plate. That is what did them in last year, a season-long difficulty in getting the timely hit and an entire lineup suddenly gone cold, and it is what did them in against the Tigers a year earlier, in another ALCS.
What Rivera can do, however, is burnish his already glistening legacy, because what the Yankees are asking, no, expecting him to do this season is something that has never been done before.
For that reason alone, it is great to have him back in camp, happy, seemingly healthy and ready to go for a 19th season. There is something endlessly compelling about watching a great athlete try to top himself, and when the athlete in question is the best that ever played his position, the quest becomes all the more dramatic.
None of the great relief pitchers in baseball history, not Goose Gossage or Trevor Hoffman, Dennis Eckersley or Lee Smith, Rollie Fingers or Sparky Lyle, has ever been able to successfully serve as a full-time closer at 43 years old.
In fact, only a handful of pitchers have even been able to nail down one save at that age.
Throw in the fact that Rivera is coming off a serious knee injury, which required surgery to repair a torn ACL in his right, or push-off leg, and what the Yankees are expecting him to do in 2013 crosses over from unprecedented to improbable.
Since Mo has made doing the unprecedented and improbable his stock-in-trade, it is not inconceivable that he can pull this off. The Yankees are so sure he can they didn't even bother to try to retain Soriano, even as an insurance policy.
And Mo is certainly making an extra effort this year, throwing a bullpen session on Wednesday, the first day of workouts, which is normally a day that reporters are asking Joe Girardi exactly when his closer will arrive in camp.
Mo has operated under the Rivera Rules for some time now -- getting to choose his reporting date, throwing a very limited number of innings, and don't ask him to get on the bus for any spring road trips -- and it is a perk he has earned through achievement and example.
No one knows what Rivera needs to do to get ready for a season better than the man himself. But even he seems to acknowledge that this spring is different, if only because there is no point of reference for the season ahead.
"I expect [to do] a little bit more," he said. "This is the first time that I've thrown the first day of spring training. It was good. I needed to do this. I need to be on the field as much as I can and stay on the field."
Rivera went through his work smiling, throwing 25 pitches off the bullpen mound, snagging grounders and hustling to first base in fielding drills with the enthusiasm of a kid half his age trying to make the team.
He looked a little creaky at times and revealed afterward that he was wearing a brace on his surgically repaired knee, a support that he expects will be his companion throughout the season.
"Just precautionary," he said, although afterward -- having been a recent recipient of knee surgery myself -- I pulled him aside and asked him about the brace. He acknowledged that it was not just a rubber compression sleeve but a gizmo with a steel bar running alongside the inner edge of the joint. "The knee was a little unstable for a while. But it's gone now. I'm just wearing it to be sure."
"We're going to watch his running and watch his PFPs [pitchers' fielding practices], and we're basically going to ask him how he feels every day," Girardi said. "If it seems to bother him ... we might change some things, but right now we feel pretty good about where he's at."
Girardi said Rivera looked like the same old Mo out there Wednesday, and Rivera said he expected to be the same pitcher he has been since assuming the closer's role for this team in 1997 after a failed attempt at starting and an apprenticeship setting up for John Wetteland for the 1996 championship team.
"Definitely, I always demand that of myself," Rivera said. "Otherwise I wouldn't be here."
He and Girardi agreed that his pregame routine of shagging batting practice flies -- the habit that sent him to the Kauffman Stadium turf writhing in pain last May -- would not change.
"Only in Kansas City," Girardi joked when asked if Mo would be forbidden to do it again. "That's part of who he is. That's part of his game that has made him great. It's his time to relax, have fun and prepare for the day, so I don't want to take that away from him."
Entering this, probably the last and very possibly the most challenging season of his career, Rivera's No. 1 goal seems to be to enjoy this one -- to cherish it, even.
"When I come here, my mind is already going to a different level, and that is winning a championship," he said. "The passion that I have for this game is what drives me. [Last year] taught me that you have to enjoy every bit of it. I definitely will enjoy this one and take advantage of it."
So should the rest of us. There's no point in worrying about what Rivera will do next season or what the Yankees would have done if he had not gotten hurt last season.
What he is trying to do this season is something no pitcher, not even Mariano Rivera, has ever done before, and that makes it special, no matter how it turns out in the end.