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In the early days of my playing career, I thought having a big league rehabber join our minor league club was a good thing. I guess that in some cases it was, seeing as how he usually bought us food after the game he played in.

You’re not fed at the lower levels, meaning most of us would eat at a gas station or fast-food joint after the game—not exactly the pinnacle of sports nutrition. Therefore, free pizza by way of rehab delivery is a no-brainer trade—totally worth giving up your spot in the rotation.

But back in my time at Single-A, a major league arm came into town offering more than pizza. His arrival bumped me out of the rotation, and to make up for it, he offered to buy me lunch the day of the start. He even let me pick the restaurant, a vain offer since the only place in walking distance from our team hotel was an IHOP.

After I ordered what I usually ordered (just a little more of it), my new big league benefactor pulled out a bottle of greenies, shook out two striped pills, popped them with no water, then offered me a pull.

I declined. I’d never had a greenie in my life, not even as a social experiment. If I were going to have one, however, I wouldn’t have one before a midday meal. I’d have it in a situation that mattered, when I needed to be acutely aware of every molecule in reality on a baseball field, outrun a humming bird or be able to see sounds—not some idle Tuesday afternoon at an IHOP over pancakes.

That night, when this rehab starter got ready to take the field, I watched him eat a few more greenies. I’d seen players eat them before. Hi-octane pills and powders were nothing new. But it was the number and the frequency with which he consumed them that was the shocking part.

Some of the other guys who had experimented with greenies told me that if they had taken six to eight greenies in a day, their heart would explode. “That’s some serious tolerance right there. This guy has had to have been doing this stuff for a while.”

Since 2005, the list of banned and tested-for substances has become more robust. You can’t pop greenies anymore—at least not overtly, using the same chemical compounds. Get caught now, and you’re hit with all manner of opprobrium, as if a stimulant were on par with murder.

But even back then, when stuff with ephedra went out the window, players—even good, upstanding, "just doing what all the other guys are doing" players—tried other things they thought they could use to get the same effect but legally.

If you’d polled them, most of the players would have probably told you that getting “up” for a game wasn’t so much cheating but part of getting prepared, like stretching or warming up.

These were the types of guys who would take Sudafed from the training room for its side effects, at least until that stuff also disappeared into illegality. Then it was canisters of supplement-store super cocktails, the kind of crap that made things of the past seem tame. When that started making players pop positive, it was on to sneaking a teammate’s attention-deficit/hyperactivity disorder drugs.

Then it was on to faking ADHD to get a prescription. Then (or in some cases, on top of) players turned to stacking Pain-Off—a readily accessible pain reliever in professional locker rooms that also contains caffeine—on top of energy drinks and anything else that creates a similar stimulant effect.

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Caffeine. Yes, I know it’s a drug nowhere near as dangerous as, say, ephedra or meth or cocaine, all of which have had their day in baseball. Most of us use it, and we all know why. We don’t feel it’s lethal or illegal; therefore, it’s not wrong if athletes want to load up on the stuff, right? I mean, it’s not like it’s steroids.

And that’s how a lot of thinking goes. It’s OK until it’s not OK. Well, it just so happens that in other sports markets across the world, caffeine is considered a performance-enhancing drug. In Japanese baseball, you can’t have much more than the serving commonly found in green tea, or you’ll test positive.

The NCAA considers overuse of the chemicals commonly found in energy drinks to be performance-enhancing. Same goes for the Olympics.

Of course, these examples speak of overuse, which connotes that moderation is acceptable. But moderation isn’t what’s happening in Major League Baseball.

In 2009, Wesley Wright, an Astros pitcher, had to be treated for severe dehydration because of overconsumption of energy drinks, an event that seemed so easily repeatable by other players that it spurned the Astros and Diamondbacks to no longer keep the drinks on hand for their players to freely consume.

And in 2012, current Padres outfielder Chris Nelson gave up energy drinks entirely after an irregular-heartbeat scare that he attributed in part to abusing them: "Too much caffeine, dehydration and stress," Nelson said. "It was like a perfect storm."

Barry Gutierrez/Associated Press

In the later stages of my career, I played with a guy who had to have three to five 5-Hour Energy shots with a king-sized Monster and a couple of packets of Pain-Off just to take the field. He knew he was going to have liver damage from all of it, but he said he’d rather worry about that when his career was over.

The big leagues were more important.

Yet, once you get to the big leagues, you have to sustain the level of performance that got you there. When you’ve been there for a while, sustaining yourself, your body begins to need the substances, regardless of the performance. When a career ends, the addiction doesn’t, and the accumulated damage sticks.

It’s not hard to understand why players like stimulants. The baseball season is long and grueling. As a matter of fact, day games after night games after cross-country flights are damn near an automatic loss.

The lifestyle is stressful and fatiguing, and it demands you not give in to any of it. And when the will is lacking, a boost of energy so strong that you must move lest you reach critical mass is a godsend. Stimulants aren’t so much a performance-enhancing drug as they are a performance-sustaining one.

Jason Grilli had the following to say on the matter to Bob Nightengale of USA Today back in 2011, which speaks to the evolution of the MLB stimulant culture and players looking for the next thing on the menu that's legally available.

"The reason guys take energy drinks is because there's not anything else (legal) to take," Grilli said. "Let's face it, the competitive edge is why the whole steroid thing got rampant."

Baseball’s rules may have stamped out most stimulants but not circumstances or behaviors that make them a logical option for players. In fact, in some cases, it has actually lionized energy drink overconsumption.

Conversely, the game also rationalizes alcohol as a coping mechanism. If every man needs an on switch, then he also needs an off switch.

There is beer in a majority of MLB clubhouses. Hell, the rookies carry it—garbage bags of ice and beer strewn over their travel suits—to the team buses so players can get buzzed before they get on a long team flight. Turn on unnaturally, turn off unnaturally—such is the big league lifestyle.

Large quantities of potential energy are consumed, often on top of other medications, in tandem with steady alcohol consumption. The end result is guys crushing energy drinks all throughout the day, just to feel “normal.” Then the same after the game with alcohol.

One has to wonder if doing greenies wasn’t simply a more efficient and effective way of satisfying a behavior that never actually left but, just like energy, simply changed form.

Dirk Hayhurst is a former pitcher who spent nearly a decade in professional baseball between MiLB and MLB. He is also an accomplished author and has appeared on Baseball America, ESPN, TBS's MLB postseason broadcasts, Sportsnet Canada and more.