Thus far in 2013, the Tampa Bay Rays are paying for their decision to trade James Shields over the winter. Their starting rotation has been uncharacteristically mediocre without him.

However, the Rays are soon going to find out whether trading Shields was worth it. The key part of the trade that sent Shields to Kansas City is on his way.

In case you missed it, the Rays made it official on Sunday that 22-year-old outfielder Wil Myers has been called up to the big leagues:

It's always a big deal whenever a top prospect gets called up, and it's a particularly big deal in this case because Myers is arguably the best hitting prospect in the game. His offensive potential is generally regarded as being enormous.

If you're still in the dark about what exactly makes Myers such a hyped prospect, myself and B/R prospect guru Mike Rosenbaum have you covered. We collaborated on a need-to-know piece about New York Mets prospect Zack Wheeler, and Myers is a perfect candidate for the same treatment.

With full scouting reports from Rosenbaum, input from other experts and some occasional chatter from yours truly, here's what you need to know about the (potentially) great Wil Myers.

The Moneymaker: The Awesomeness of Myers' Bat

The Rays were able to bring themselves to part with Shields for one very simple reason: They saw a chance to acquire a kid who might become one of the league's great hitters.

This was hardly a misguided notion. Myers exploded to the tune of a .314/.387/.600 line and 37 home runs in the minors last year, and he was hitting .286/.356/.520 this season before he got the call. He boasts the numbers of a potentially lethal hitter.

Rosenbaum says Myers boasts the goods, too:

At 6’3” and 205 pounds, Myers is a lean athlete with a tapered build, despite having added considerable muscle since the end of the 2011 season. More significantly, his upper body—especially his wrists and forearms—is loaded with quick-twitch muscles that cater to the explosiveness of his right-handed swing.

Jason Parks of Baseball Prospectus (subscription required) and ESPN's Keith Law (subscription required) have also noted the strength and quickness of Myers' wrists, and it's an asset that shows up on video.

There's a slow-motion replay of Myers' swing contained in a video of a double he hit in spring training over at MLB.com. I can't embed that video here, but I do have a GIF of the key parts:

You can see just how still Myers is at the plate when he swings. He's strong all over, but it looks like the only parts of his body generating power are his arms.

And power is something he can generate a lot of, for the record. Here's the Rosenbaum report on Myers' pop:

Although he always possessed plenty of raw power, Myers didn’t truly learn to tap into it until last season when he adjusted his setup at the plate; he raised his hands slightly to eye level and employed a more open stance. Myers was suddenly able to clear his hips and turn on inner-half velocity with ease, showcasing plus bat speed while effortlessly dropping the bat head on the ball and driving it with more consistent backspin carry to all fields.

Baseball America made a similar remark about Myers' stance at the plate, saying that he began "setting up more upright and working on back-spinning the ball for more carry." Keith Law noted that Myers' stride is also longer than it used to be.

But enough with words. Would you like to see Myers turning on inner-half velocity with ease?

Very well then. You can go over to MiLB.com to see him absolutely murder a 91 mph fastball on the inner half of the plate, but I've once again prepared a GIF:

You can see that Myers let the ball travel pretty close to the catcher's mitt before he unleashed his swing, and he hit the ball right on the screws. It's hard to tell exactly where this ball landed in the full video, but it clearly landed a long way from home plate.

This is roughly what the Rays are hoping for from Myers going forward. He has the ability to hit for power, and he certainly goes to the plate with the idea in mind to hit for power.

This approach does have some drawbacks, but they're not quite deal-breakers.

Good and Bad: Myers' Approach at the Plate

Believe it or not, Myers wasn't always regarded as having huge power potential. He hit only hit 14 home runs in his first full minor league season back in 2010. After an injury-riddled 2011 season saw him hit only eight home runs, Baseball America (subscription required) was only willing to grant that Myers had the potential to hit 20-to-25 homers per year down the road.

That sounds conservative now. Myers looks like an elite power prospect, and Rosenbaum says he has himself to thank for that:

Myers’ power surge in 2012 stemmed from alterations made to his approach. Previously, his swing and approach was geared towards consistent contact to all fields and led to a high number of extra-base hits. However, in accordance with the aforementioned mechanical adjustments, the 22-year-old also adopted a more aggressive mindset at the dish. He began to take bigger hacks in all counts as he looked to punish the baseball rather than feel for solid contact from line-to-line.

The changes have obviously had the desired effect. All you need to do is take one look at his power numbers, though you should also feel free to go back and watch the video of that home run again.

However, there's a catch. Here's Rosenbaum:

Myers’ adjustments come with a drawback, as it resulted in a career-high strikeout rate and made him prone to chasing quality secondary offerings on the outer half. That being said, it’s important to remember that 2012 was the first season that Myers applied all of the changes in games. Therefore, as he continues to grow more comfortable with the swing and more knowledge of how pitchers will try to exploit his weaknesses, the high strikeout total should gradually come down. However, it’s likely that he’ll always have a degree of swing-and-miss to his game.

The numbers tell the story. Between 2009 and 2011, Myers' K% (strikeouts/plate appearances) was 18.9 percent. In 2012, it was 23.7 percent. In 2013, it was 24.6 percent.

But like Rosenbaum says, it's not a given that Myers is going to be an Adam Dunn- or Curtis Granderson-esque high-strikeout guy his whole career. There's even some promise right now that he won't be, as Baseball America noted that Myers is perfectly capable of shortening up and hitting the ball to the opposite field.

He proved as much in the Futures Game last year. Watch the highlights at MLB.com and check out what Myers does at around the 15-second mark. I can't embed the video here, but I do have a GIF:

That's a 2-2 fastball that Myers allowed to get very deep in the zone before he flicked his wrists and poked it into right field for a base hit. He may be an elite power prospect, but he was essentially doing a Derek Jeter imitation on that pitch.

I'm willing to take Rosenbaum's word for it that Myers is always going to have a swing-and-miss element to his game. Most power hitters do. But there are power hitters who will look to go the other way on occasion in two-strike counts, and that's a line Myers could fall into.

If he does, he's going to pick up a few extra hits here and there and will thus establish himself as both a power and an average threat. A rare breed indeed.

Now, as for the other side of the ball...

Playing the Field: Myers' Defense

Had things gone a little differently, we could be talking up Myers as an even rarer breed: a great hitting prospect at the catcher position.

But things didn't go differently. Myers was a catcher before, but he's an outfielder now and he's not going back.

As for how Myers projects as an outfielder, here's the Rosenbaum report:

A former catcher who was moved to the outfield prior to the 2012 season, Myers’ athleticism allowed him to make a smooth transition to the new position. While he has played center field in the past and could probably play there in a pinch at the highest level, his defensive actions, range and instincts are better suited for a corner outfield position. Meanwhile, Myers’ plus arm strength has always been his strongest defensive asset and profiles as a clean fit in right field.

The notion that Myers is best suited to play right field is the general consensus among the experts. Keith Law, however, says that Myers still has work to do even in right field:

On defense, he can fake center field but belongs in right; he's athletic enough to handle it with a plus arm but needs work on his reads, as you'd expect from a player who was a catcher coming out of the draft.

If you want a glimpse of what Law means when he says that Myers needs to work on reads, go watch a video of Myers making a diving catch in the outfield over at MiLB.com. He took a decent route to the ball, but he didn't appear to go into full-throttle mode until moments before the ball was going to land. Had he been going full speed the whole way, he may not have needed the dive.

While Myers probably could be an average center fielder down the road, it makes a lot more sense for the Rays to put him in a position to be an above-average defender in right field. It is indeed a better fit for his athleticism and his arm strength—sorry, no video footage that I could find—and it just so happens that the Rays could use a defensive upgrade in right field.

Matt Joyce is having a terrific year offensively, but not defensively. Per FanGraphs, Joyce has minus-eight Defensive Runs Saved in 2013. That includes minus-one Outfield Arm Runs Saved.

We could see the Rays making Joyce their everyday DH so they can have Myers in right field on a regular basis. That could give them a very solid defensive outfield, as Kelly Johnson has panned out to be a surprisingly good left fielder and Desmond Jennings and Sam Fuld are both solid in center.

Myers has played right field exclusively in the minors this year, so he should be comfortable out there already. If the Rays continue to play him there at the major league level, he should only become more comfortable and, thus, more of a defensive asset.

For now, the Rays will take whatever numbers Myers can provide with his bat. And given what he packs on an offensive front, the odds are pretty good that the Rays won't be disappointed.

Note: Stats courtesy of Baseball-Reference.com unless otherwise noted.

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