Harper, the National League Rookie of the Year for the Nationals, was a pivotal piece on a playoff club that had the best regular-season record in the game.
Their impact, then, was instantaneous. The future forecasts for their feats became the present-day Doppler radars.
Thanks to the meticulous MVP debate, it is entirely possible you can recite Trout's WAR stat right now. Thanks to the fun factor of social media, you likely remember the "That's a clown question, bro" meme Harper started.
That's all well and good, of course. But in the long run -- and from a pure baseball perspective -- we're likely to remember the robust rookie seasons of Trout and Harper more for two signature moments that told us everything we need to know about them as athletes and give us all the reason in the world to be excited about their future.
Here's what we'll remember.
May 6, Nationals Park
: A little part of you can't help but hate this Harper kid, right?
He was on the cover of Sports Illustrated at 16, billed as "Baseball's Chosen One." He got ejected from a National Junior College World Series game, likely costing his team a title. He blew a kiss at an opposing pitcher after hitting a home run in the Minors. He wears eye black down to his ankles. He is the embodiment of the overindulged, overhyped, overzealous 21st century athlete.
And about a week and a half into Harper's big league career, Cole Hamels just intentionally plunked him with a fastball in the middle of the back.
And that little part of you roared with approval.
But wait, what's this? Harper is just stretching his back and walking calmly to first. He's not jawing with Hamels. He's not acting outraged or even the least bit annoyed. He's doing what countless other rookies have done -- taking the brunt of this "Welcome to the big leagues" moment and doing so with class and poise.
And wait, what's this? Harper is at third now. He's taking his lead off the bag. And when Hamels makes a half-hearted pickoff attempt at first base, Harper bolts. He covers the final 80 feet of the 90-foot distance between third and home in a flash, sliding in ahead of Carlos Ruiz's tag.
Maybe that little part of you hated Harper beforehand. But if you're a true baseball fan, if you like to see players show headiness and hustle mixed with more than a modicum of maturity, you couldn't hate him afterward.
Not even Hamels could.
"That was probably the most impressive thing I've seen," Hamels said months later. "Unfortunately I had to be on the bitter end of the stick on that. But you know what? It definitely shows you a lot about what he does, and I think it's taught me something about baseball, to push harder and play harder. I can thank him for it, too."
The Nationals are thankful that Harper handled the enduring glare of the spotlight so well this season. Veterans in the Nats' clubhouse said they saw enormous strides in his maturity. He proved to be well-coached in how to handle the media, and he proved to be a good teammate, even as he slumped for a good part of the summer. The statistical results, while inconsistent, were among the best in history for a 19-year-old. What was consistent was Harper's hustle and determination.
He might have been dismissed by many as representative of the "new school" of athlete. But if anything, his attitude was decidedly old school. Harper wants to beat you, and he will use every bit of his baseball intellect and God-given athletic gifts to do so.
"I followed him a little bit since he was 14 or 15, and he's always been up to the task of competing with older, stronger [players]," Davey Johnson said. "And he's always handled himself really good. I mean, he had a few blips on the screen this year, but I think, by and large, he got to gain the respect of not only the opposing players but even the umpires in the league."
We saw that on May 6.
June 27, Oriole Park
: Baltimore is the closest AL city to Trout's hometown of Millville, N.J., so if it seems there are a few more Angels fans in attendance at Camden Yards on this clear, 85-degree night, your eyes and ears do not deceive you. More than 1,000 of Trout's friends and family members have made the trek here for the two-game set against the O's.
But by this point, Trout's fan base is spreading well beyond Millville. After an initial break-in at the end of 2011, he was called back up to the big leagues two months ago. And in the time since, he's batting .335 with a league-leading 21 stolen bases, rescuing the Angels from an agonizingly slow start.
Trout is 20 years old, clean-shaven, mild-mannered, humble and having the time of his life. As absurd as it seems, he may already be one of the best players in baseball.
"You can't ask more of a player," his manager, Mike Scioscia, told reporters last week, "at any age."
No, but Trout keeps delivering more. And his legend grows accordingly.
It will grow, quite literally, by leaps and bounds on this Maryland night.
Bottom of the first, one out, Angels up, 1-0, Orioles at the plate. Jered Weaver leaves one hanging for J.J. Hardy, and Hardy gets a hold of it. The ball drifts deep to right-center, and you can forget about it. It's a goner. Given the speed of the ball off the bat, Trout's positioning and the sun and the shadows, there's no way he even gets to it -- let alone catches it -- right?
Words won't do justice to the speed with which Trout gets to the wall and the agility he shows in leaping and reaching over the Southwest.com sign to haul the ball in. We'll have to settle for the video clip
. But suffice to say, it's the catch of the year and probably one of the best catches of the past decade. Immediately, it conjures up a memory of another Angels outfielder -- Torii Hunter -- from his Twins days, when he famously robbed Barry Bonds at the 2002 All-Star Game.
"Just watching him go up and make that catch, I got chills," Hunter will say afterward. "I was fired up and I was high-fiving, we elbowed each other, we did everything. I felt like I caught the ball, because I just remember myself doing that. To see Trout do that, a guy that comes and talks to me about a lot of different things, it's awesome. It's awesome. Tears almost came down my face. But I'm a man, I don't cry."
Trout could make a grown man cry with his feats on the field, which on this night include four hits in a 13-1 Angels rout.
But more than the offensive impact (and with a .963 OPS, Trout will provide plenty of it from the Angels' leadoff spot this season), it is Trout's overall athletic ability that stirs the senses. It won't be enough to earn him an MVP nod over Triple Crown winner Miguel Cabrera, but it will be more than enough to earn the respect of those in the league and those in the stands. And if you want a tell-tale moment in time to define Trout's greatness, well, here it is. He caught the uncatchable, and the baseball world -- to say nothing of those 1,000 members of the Millville community -- applauded.
Somehow, one gets the sense we'll be applauding Trout and Harper quite a bit in the coming years.