Fifteen years, three months, and 28 days after he recorded career save number one, Mariano Rivera notched career save number 600 last night. It came with very little fanfare given the historical significance, as he became just the second man in history to compile that many saves. An individual save, or even a collection of saves over the course of a season is generally meaningless, but racking up 600 of them over a 16-year career indicates durability and longevity in a job known for the exactly opposite. Of course, there’s a chance that all of this might not have been.

It seems like every all-time great has an “almost traded” story, and Rivera is no different. He has several, in fact. The Yankees tried to swap him for David Wells in 1995, and two years later they were willing to put him in packages for Randy Johnson and Pedro Martinez. Mo already had one year of closing under his belt by the time the last two deals were discussed, and the team’s plan was to acquire a high-end starter and sign a free agent like Roberto Hernandez to close. Even before the trade talk, Rivera successfully came back from major elbow surgery, a Tommy John surgery-like procedure that reinforced the elbow ligament. That’s an obstacle we often understate.

Criminally underutilized by Buck Showalter in the 1995 ALDS, Joe Torre took the reigns the following year and used Rivera in a way that would have caused most men to crumbled. Mo threw 107.2 IP over 61 relief appearances in 1996, a workload completely unheard of these days, but he excelled. A 2.09 ERA and a career high 10.9 K/9 earned Rivera both Cy Young and MVP votes (finished third for the former, 12th for the latter). The Yankees went on to win the World Series with Rivera’s help, then installed him as their closer the next year.

That first year in the ninth inning went very well (1.88 ERA), but a blown save (in the eighth inning) of Game Four of the ALDS ended his season on a sour note. As silly as it sounds now, that homerun by Sandy Alomar had people wondering if a quiet fisherman from Panama was a viable closer for a perennial contender. Rivera proved all the doubters wrong in subsequent years, and his postseason track record is the stuff of legend: 139.2 IP and a 0.71 ERA. He’s allowed four postseason runs in the last nine years.

Of course, Mo has had some pretty high profile blow-ups as well. Years after the Alomar homer, he blew the save and took the loss in Game Seven of the 2001 World Series, in part because of his own defensive miscue on a would-be sacrifice bunt. Ironically, the finishing hit was nothing more than a weak little broken bat looper, one of Rivera’s trademarks. He also blew back-to-back saves in the 2004 ALCS. When you make that many appearances in the playoffs, slip-ups are bound to happen, but thankfully Mo’s slip-ups have happened with great irregularity.

“I think people will realize it when he’s no longer here,” said Derek Jeter after last night’s game, speaking about how important Rivera is (and has been) to the Yankees. “Yankee fans have been spoiled, baseball fans watching him, us as teammates. You don’t see this. We don’t take him for granted, but I think a lot of people may.”

Whether you realize it or not, we’re all part of the group that takes Rivera for granted. It’s human nature, he’s been so automatic for so long that we can’t help but expect greatness. That’s why when he goes through his annual struggles in April and August, people are quick to question his greatness or even call him finished. At 42 years young, Mo is as dominant as ever. His strikeout rate is close to a whiff per inning (8.5 K/9) after a drop last year, and his walk rate is the second lowest of his entire career (1.1 BB/3). With 3.0 bWAR to his credit, he’s already surpassed last year’s value (2.9) and figures to pass 2009′s value (3.1) before the end of the season.

The Yankees are close to clinching yet another playoff berth, and once the postseason begins, they’ll have one advantage over any team they face, the one advantage they’ve had for the last decade and a half. Rivera is unmatched in the ninth inning and has been for basically his entire career. As unfair as it seems, we expect greatness from Mariano, but only because he’s delivered time and time again. Six hundred saves is a nice round number, but he didn’t need that milestone to validate his greatness.

Say your prayers... (AP Photo/Kathy Willens)

As Yankees fans, we’re privy to seeing a lot of great things on the field and a lot of history being made. Just this year we saw Derek Jeter pick up his 3,000th career hit in a way only one other man has done (a homer), and last year it was Alex Rodriguez‘s 600th career homer. We’ve seen Roger Clemens get his 300th career win and Mike Mussina his 2,800th career strikeout in recent years, but one little piece of history seems to be flying under the radar late this season: Mariano Rivera is closing in on the all-time saves record.

Yesterday’s win gave Rivera his 38th save of the season and 597th of his career. Only the great Trevor Hoffman has closed more ballgames in his time, a total of 601 career saves. Lee Smith is a distant third on the career saves list at 497. With 23 games left to play and the Yankees piling up the wins down the stretch, there’s a pretty strong chance that Mo will become the second member of the 600 save club and even surpass Hoffman as the all-time saves king before the season ends. It’s not a lock, but it’s certainly possible.

Perhaps the lack of buzz surrounding Rivera’s pursuit of the record has to do with saves being a silly stat on a micro level (like wins or RBI). On a macro level though, over the course of an entire career, they do bear some meaning. For one, a saves total of that caliber indicates longevity in an occupation that rarely has any. We see it every year, closers come and go at a moment’s notice, losing their jobs to the next big thing who eventually loses his job to the next big thing, and so on. The heightened awareness of the ninth inning in today’s game puts any closer meltdowns in the national spotlight, so teams are quick to make a change. Longevity and durability in the role with perhaps the greatest turnover in the game is impressive.

On the other hand, perhaps it has to do with the fact that we already know Mariano is the greatest closer of all-time, with or without the saves record. With all due respect to Hoffman, Mo has allowed 73 fewer earned runs and walked 33 fewer batters despite throwing 113.2 more innings (in a tougher division) in his career. That doesn’t even count postseason heroics, which are obviously influenced by the teams they played on. Add in Rivera’s 42 career playoff saves, and he’s at 639 compared to Hoffman’s 605. But again, you can’t hold the fact that Hoffman played on a generally bad to mediocre team against him.

With any luck, Mariano will pick up those last five saves to surpass Hoffman’s all-time record at some point before the end of the season, just so we can watch the celebration and all the recognition that comes along with it. If he doesn’t get it this year, well that’s fine too, because we already know that Mo is the greatest reliever of all-time and don’t need the extra validation. I would like to see him get the record in the coming weeks because Rivera is perpetually humble and always team-first, and I want to see him get honored and celebrated for his accomplishments. Like Jeter and his 3,000th hit, it’s okay for Mo to sit back, soak it all in, and make it all about himself for once.

Mariano Rivera spoke to Bob Costas and his great hair prior to last night’s game against the Red Sox, and the two discussed a wide range of topics including retirement, a desire to play center field, and a whole lot more. Check it out.