Mariano Rivera. Babe Ruth. Christy Mathewson. Sandy Koufax.

Jeremy Affeldt?!

Even now, three World Series rings later, it sounds almost comical when I hear my name mentioned among some of the greatest players in baseball history. Those guys were elite, the best of the best; every one of them is a Hall of Famer who left his indelible mark on the game. Me? Not so much. Yet when you check the all-time postseason ERA rankings, quite inexplicably, there I am.

0.86.

That’s my career ERA in the playoffs. Only incomparable New York Yankees closer Mariano Rivera and St. Louis starter Harry Brecheen (they called him Harry the Cat, coincidentally) compiled better marks during their postseason runs.

Most people don’t believe me, but I really didn't do anything different on the mound in the postseason than I did during the regular season. My success in the most critical of situations was just as easily attributable to my managers putting me in good positions to succeed and my defense making plays behind me as it was because of anything I did out there.

In leaving the game, I walk away secure in the knowledge that I accomplished almost everything I ever set out to do. I gave it everything I had out there, and I played the game the right way—not necessarily in compliance with some antiquated and silly "code," but cleanly, and with honor and dedication to my craft. Along the way, I got to play both with Hall of Famers and guys who only got called up to the Show for a cup of coffee. I marched in three world championship parades in San Francisco, proving once again that you don't have to throw hard to get the best hitters in the world out.

While I am very excited to begin the next phase of my life and make up for a lot of lost time with my wife, our three sons, family and friends, I absolutely will miss my teammates, the thrill of performing before tens of thousands of people, and the indescribable sense of purpose that comes along with being a professional athlete. Still, I'd be remiss if I didn't also share what I won't miss about life in the Bigs. After all, why else would you care what some creaky-knee'd lefty reliever has to say?

Here we go.

5. The City of "Brotherly Love"

Hang on, I know what you're thinking: Jeremy, do you have any idea how dangerous it is to insult the entire city of Philadelphia?! And yes, I know. I know all too well.

So first, let me be clear. Philly is a great sports town, with passionate fans and a palpable energy. The problem, though, is that the city, more than any other I've played in, seems to condone and almost revel in its fans crossing the line. Nowhere else in this country—again, based on my experience as a 14-year major leaguer and the conversations I've had with other players—is the opposition treated in such a repeatedly vile and borderline threatening manner.

We are out here to play a game, and even though we are paid handsomely to do so, professional athletes should not be subject to vulgarity, personal attacks or epithets. Sadly, in Philadelphia, this kind of fan conduct is far too typical. The irony is, while Phillies fans succeed in making many players dread traveling there, they also (not surprisingly) impact the decision-making process of those same players in free agency.

Sure, it's great to play for a rabid fan base, but after experiencing firsthand how powerful that fervor can be when it is channeling extreme negativity, it really makes you think twice about where all that collective anger comes from, and whether you want to subject yourself and your family to that all the time.

4. Wrigley Field

Yeah, that's right, I said it.

Admittedly, the home of the Chicago Cubs is a national treasure. Visiting that ballpark should be on any baseball fan's bucket list, and for good reason. On the surface, the place is gorgeous, and the building is a virtual time machine. But when you take a closer look—and I've read quite a few accounts from the fans' perspective that seem to back my sentiments—all that shimmers most certainly is not gold.

While I realize that Wrigley is now undergoing a multiyear, multi-faceted renovation plan, I can only speak from my own experience. When I was with the Cincinnati Reds, we played a lot of games on the North Side, and I can tell you that the player facilities are an abomination. Not just by today's standards, where players often find themselves taking advantage of luxurious clubhouses with every modern amenity imaginable, but by any era's standards. Wrigley's locker room (I can't even really call it a clubhouse) is tiny. It's virtually impossible to squeeze players, coaches and equipment staff in there at once, and when it rains—this happens quite often in the Chicago summertime—it's absolutely unbearable.

And that mound. Every stadium has its quirks and home-field advantages, but the hill at Wrigley is another thing altogether. Not only is it different than other major league mounds, but it's also different than the park's warm-up mound! Maybe my feelings have a little something to do with me being winless at Wrigley (5.59 lifetime ERA!), but still, I won't miss that place.

3. The travel

By far the most difficult thing about being a major leaguer today is the travel. It's easy to look at all the money we make playing a kid's game and say, "Whatever you say, Jeremy. It must be super hard to fly around on those decked-out charter flights all the time."

No, we don't have to stand in line at security in the airport; we don't have to pay to check that first piece of luggage; we don't have to be told by hotel reception that all the rooms are booked and there's nothing they can do. Then again, we do have to take flights at 2 a.m. across three time zones, often leaving only a few hours to get some sleep before we are expected to go right back to work in a job where failure to deliver peak performance might put that job in jeopardy. We do have to be separated from our wives and kids for weeks on end. We do have to miss important, precious moments at home, year after year, with no way to explain to a child why we couldn't be there for them. Is it all relative? Absolutely. But that doesn't make it any easier.

In the end, the life of the professional athlete is the life we have chosen, and each of us is blessed to have been given the opportunity to compete at the highest levels and get paid for it. But that doesn't mean that the life doesn't wear you down over time, which is precisely why I will be staying in my own zip code for a few months after the final game of our season—and my career—this Sunday afternoon.

2. The drug tests

Two things to get out the way right off the bat: 1) I have never used performance-enhancing drugs; and 2) Major League Baseball is 100 times cleaner now than it was when I first broke in as a pro back in 2002.

Notice how I didn't say the game is 100% clean. As long as science keeps coming up with ways to avoid PED detection, some guys—no matter how harsh the penalties—are going to ignore the risks to their reputation, physical well-being and their bank accounts. They will always "improve" themselves by any means necessary. While I can't say for sure how guys are still on something today, I do know that it's a lot less than the roughly 40% of players I believe were cheating 15 years ago.

Make no mistake: I don't believe in using drugs to gain a competitive advantage, even though I know exactly why so many players did it. It was selfish of them, though, and unfair to those of us who weren't doing it. By inflating (or, in the pitchers' cases, deflating) their numbers, PED abusers were taking food off my table, rendering my accomplishments and statistical achievements less meaningful—and certainly less useful when negotiating my contracts.

It's fantastic that the game has since been cleaned up, of course, but the situation never should have been allowed to get so out of control. In fact, because of the years of negative coverage and bad publicity, in today's environment—despite MLB's apparent confusion about the meaning of the word "random" when it comes to testing—any hitter or pitcher who excels becomes a suspect. And that makes them subject to more frequent testing. I get that the powers that be view this is a necessarily evil, but the practice also has real consequences.

For example, spending a weekend playing at altitude in Colorado leaves players dehydrated, so when MLB's testing officials show up at 11:30 p.m. after the Sunday night game has ended, it's literally impossible to provide them with the mandated urine sample. When ya' gotta go, ya' gotta go, but when you can't ... you can't. That forces the player to stay in the bathroom, being watched like a hawk, for as long as it takes to do his business. There is no dignity in that, but remember: per the Collective Bargaining Agreement, failure to take the test is the same thing as failing the test.

Thankfully, the next time I pee in a cup, it will be for my MLB pension physical two decades from now.

1. The incessant showboating

Nowadays, all you hear about is how "baseball is dying," and "the game is too slow and boring," and "MLB just needs to let these guys have more fun." Believe me, we players hear all of that media-driven chatter, and we're not buying it. Yes, baseball isn't the NFL (that's a good thing, in my opinion), or the NBA, where fans can rock the gear and emulate the stars much more easily.

But what baseball does have, that those other sports largely do not, is tradition. And while the history of the sport has seen more than its fair share of troubling (institutional) incidents, that is precisely why the game remains so important to so many Americans. Baseball is a reflection of ourselves, our struggles and triumphs, our perseverance.

This is why the recent trend of "look at me" machismo, mostly via these elaborate, annoying and overindulgent hand signals and signs, irks me so much. Yes, let's celebrate the game of baseball, and, if warranted, celebrate our on-field accomplishments with genuine shows of emotion. When you smack a double into the gap to take the lead in the eighth inning, by all means, pump your fist and praise your maker in the sky. But when you flash self-congratulatory signs after a meaningless first-inning single—or, even worse, a walk—you're clowning yourself and not representing your club or your teammates very well.

Despite this, as I ride off into the sunset, I truly believe the future of baseball is in great (if not overly demonstrative) hands. Here's hoping the game's young stewards take time off from patting themselves on the back, though, if only to take notice of how us old guys do things.

Jeremy Affeldt is a three-time world champion pitcher with the San Francisco Giants and author of To Stir a Movement: Life, Justice, and Major League Baseball

(Editor's Note: Portions of this essay were adapted from an earlier piece published by the author at The Cauldron.)

​