Which rookie sluggers could have a big impact in the postseason?

The Yankees' Greg Bird and the Mets' Michael Conforto are among four hard-hitting rookie sluggers who could have big impacts in the playoffs.

Rookie call-ups can benefit MLB playoff contenders by providing speed, defense and — perhaps most crucial of all — energy to veteran-laden lineups worn down by the long regular-season slog.

But forget all that stuff for the moment. We’re here to talk about power. Raw, brute, adrenaline-surged strength. Show us the kids who hit lasers, frozen ropes, dingers, moonshots, taters, mashers, zim-zams, zorks, and scallywops; the guys who've inspired a treasure trove of made-up words to describe baseballs flying faster and farther than we thought possible.

This season, MLB Advanced Media introduced a new way to measure power to the masses:batted ball velocity ("BBV"). No longer must we rely solely upon antiquated metrics like fly-ball distance or, even worse, the naked eye, to judge a hard-hit ball. We’re now able to gauge the actual speed of the ball as it rockets off the bat head.

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A quick glance at the leaders in BBV (minimum 50 ABs with data) tells us much of what we already know: Sluggers like Giancarlo Stanton (No. 1: 97.73 MPH), Miguel Cabrera (No. 8: 93.75 MPH), and Jose Bautista (No. 9: 93.65 MPH) hit baseballs harder than most of their peers. What we might not have guessed, however, is the unexpected quartet of rookies who cracked the top 10 in what is called “exit velocity.” Each of these players is 22 years old, each was called up in the second half of 2015, and each is making an impact on a playoff contender.

So, who are these young interlopers? And can they keep crushing the ball to this degree in the postseason?

Greg Bird, New York Yankees

(Avg. BBV:  94.75 MPH [No. 2])

2015 stats: 137 PA, .256 BA/.336. OBP/ .562 SLG, 7 2B, 10 HR, .306 ISO

Going strictly by prospect rankings, Greg Bird is the player least likely to wind up on the list—which probably says less about Bird than it does about the way young first basemen are evaluated. When it comes to position players, first base has long been considered the last line of defense; a place for teams to stick sluggers who can’t field any other position. So it was with Bird, a converted catcher noticeably lacking in game-changing athleticism.

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But he can hit. Bird shot through the minors on the strength of his batting eye. And while he never put up eye-popping home run numbers, scouts still rated him as having plus raw power.

That muscle has been on display ever since Bird was called into regular duty for the Yankees to replace the injured Mark Teixeira. Indeed, it’s nearly impossible to overstate his value to the very dinger-dependent New York lineup: Since August 19, six of Bird’s home runs have given the Bombers a lead — including a three-run, 10th-inning jack in Toronto that staved a potential sweep and sent even hardened Yankees fans running around their living rooms, flapping their arms ka-KAW-ing like crazy people.

Can Bird parlay this power surge into a productive Big League career? Or is he destined to join Kevin Maas in the annals of all-time flashes in the pinstriped pan?

There’s plenty of reason for optimism. Back in July, Fangraph’s Chris Mitchell crunched the numbers in search of minor league prospects who fit the same power-and-patience profile as Diamondbacks superstar Paul Goldschmidt, himself once a lightly regarded prospect. Greg Bird was on that list, alongside the likes of Miguel Sano and Kyle Schwarber. He’ll probably never amount to much on the defensive end, but he might well belt his way to a fine career in the Majors. Ka-KAW, indeed.

Miguel Sano, Minnesota Twins

(Avg. BBV:  94.32 MPH [No. 3])

2015 stats: 284 PA, .277 BA/.394 OBP/ .562 SLG, 16 2B, 17 HR, .285 ISO

[youtube:https://youtu.be/MkfXSVGps6U]

Sano, a powerful righty, has borne the brunt of huge expectations ever since the small-market Twins handed him a record-breaking $3.15M signing bonus at the tender age of 16. (Sorry, just a second ... SIXTEEN!) He was a consensus top-10 prospect in 2014, before Tommy John surgery cost him a full season. As a teenager, he was the subject of a documentary narrated by John Leguizamo. (Sorry, just a second ... John Leguizamo!)

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Why all the hubbub? In a word: pure power. O.K., two words. It’s the kind of power inherited by only a select few and passed down directly from the baseball gods. Each of the four players on this list was rated last winter by Fangraphs as having above-average raw power on the 20–80 scale, but Sano topped the scale at the maximum 80. Teammate Torii Hunter, who has seen a thing or two in his longer MLB career, describes Sano’s power as “almost a little bit of The Hulk combined with some strong-ass animal.”

That once-in-generation power has been on full display since early July, when Sano was called up from Double-A to boost an overachieving Twins club that had started to flounder. Minnesota likely won’t make the playoffs, but Sano’s bat has kept them in contention far longer than anyone expected.

Nominally a third baseman, Sano is projected to move to first in the near future. Like Bird, he will have to put up crazy offensive numbers to achieve elite value, but barring injury, he is likely to do exactly that — thrilling fans with his feats of strength and keeping Leguizamo employed long after they stop making Ice Age movies.

Kyle Schwarber, Chicago Cubs

(Avg. BBV:  93.82 MPH [No. 6])

2015 stats: 241 PA, .248 BA/.353 OBP/ .519 SLG, 6 2B, 1 3B, 16 HR, .272 ISO

Can we talk about this dinger for a moment? Schwarber's cannon shot simply boggles the imagination. There are only a handful of right-handed batters capable of reaching the ever-present swarm of people waiting in front of Citizen’s Bank Ballpark’s Tony Luke’s, yet here is a rookie cutting the line—with an opposite-field bomb, no less. Can’t say that I blame him, though—those are some damn good cheese steaks.

As you know, the Cubs do not lack for drool-inducing young hitters. Kris Bryant recently set the franchise record for homers by a rookie, and Jorge Soler ranks 25th on the exit velocity list. Still, none of them sock the ball with quite the ferocity of Schwarber, Chicago’s premiere catching prospect.

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Though Schwarber’s power has never been in doubt, his defense remains a real question mark. Called up to replace injured backstop Miguel Montero, Schwarber has been all but removed from behind the plate ever since Montero returned from the DL. It’s the bat that’s kept Schwarber in the lineup, mainly as a stopgap left fielder.

Defense aside, that power will play anywhere, and with the young Cubbies on the verge of a one-game Wild Card showdown with the Pittsburgh Pirates — possibly at pitcher-friendly PNC Park — manager Joe Maddon is best served worrying about Schwarber's long-term position over the off-season.

Michael Conforto, New York Mets

(Avg. BBV:  93.77 MPH [No. 7])

2015 stats: 161 PA, .284 BA/.360 OBP/.532 SLG, 11 2B, 8 HR, .248 ISO

The Mets are the yin to the Cubs’ yang — they too have an incredible stable of young talent, but most of them are pitchers. Steven Matz and Noah Syndergaard have joined Matt Harvey and Jacob deGrom to form an enviable rotation of young power arms.

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For the first half of the season, New York very much played like a club whose talent was pitching: Hovering around the .500 mark, weighed down by an offense that needed another bat or two just to reach the level of “pathetic.” Since July, however, that offense has roared to life: Trade deadline acquisition YoenisCespedes has set the hearts of Met faithful aflame, while Travis d’Arnaud and David Wright have returned from the disabled list to offer timely contributions. But don’t discount the importance of Conforto, New York's top hitting prospect, brought up from Double-A on July 24. He’s absolutely crushed right-handed pitching, while playing a surprisingly solid left field. Hell, he even defeated cross-town rival Greg Bird for The New York Post’s made-up title of “Most Coveted New York Phenom.”

Given the Mets’ roster construction, and the bankrupt, be-Madoff’ed makeup of their owners, Conforto is crucial to his franchise’s future. Amazingly, the Mets are so pitching-rich that they can afford to lose a Harvey or Syndergaard and still boast an elite staff, but that lineup remains much more vulnerable. It remains to be seen if the Wilpons will pony up the money to re-sign Cespedes in the offseason, and if they do not, they will have to lean heavily on youngsters like d’Arnaud (a tremendous, injury-prone talent) and the increasingly intriguing Conforto.

Given what he’s shown already, though, betting on Conforto’s bat may not be the worst thing in the world. Predicting a young hitter’s power potential is one of the most frustrating tasks in scouting. Some prospects add muscle, but not power; others hit bombs in batting practice, but never in games. “Baseball is 90 percent mental," Yogi Berra once said, "and the other half is physical.” Whatever comes of this quarter of raw power-laden sluggers, we know they have the second part down pat already.