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Which National League rookies are likely to make biggest impact?

Led by Rookie of the Year front runner Corey Seager, here are five potential impact rookies to keep an eye on in the National League this season.

Corey Seager is ready for prime time. Last September, the Dodgers brought up their top prospect from Triple A Oklahoma City and watched him seize the opportunity—and the starting shortstop job—from a broken-down Jimmy Rollins as the team closed out the National League West race. The 21-year-old younger brother of Mariners third baseman Kyle Seager hit a sizzling .337/.425/.561 in 98 at-bats over 27 games—not enough time to forfeit his rookie status—and landed atop all of the major prospect lists this spring. With nothing standing between him and a starting job, he's the obvious choice to head our list of the NL's impact rookies.

Not every top prospect is headed for the majors this season, of course, and many nonetheless have obstacles in their paths, whether they be service clocks, veteran stopgaps or finishing touches at Triple A. What follows here is a look at five such youngsters from the Senior Circuit who figure to spend more time in the majors than the minors and to make their presence felt as they do. We'll have a similar complement of AL rookies in our next installment.

Players are listed according to their highest rank on any of the big four prospect lists, namely Baseball America, Baseball Prospectus, ESPN or; a hat tip to the hard workers at those sites whose observations drive the scout-based information herein. Note that while players with professional experience in Japan, South Korea and Cuba are considered rookies and placed on some prospect lists, I’m not considering them here.​

Corey Seager, SS, Dodgers

BA: 1; BP: 1; ESPN: 1; MLB; 1 (Average 1.0)

The No. 18 pick of the 2012 draft out of a Charlotte, N.C. high school, Seager is roughly 6 1/2 years younger than his Seattle-based brother, and he's much bigger, listed at 6'4" and 215 pounds. That size will make him about as big as any player ever to play the position regularly. Via's Play Index, Carlos Correa, Cal Ripken Jr. and Andy Fox are the only players listed at 6'4" who have logged at least 80 games at short in the majors, and only 11 players standing at least 6'2" and of that weight or greater have stuck there—most notably Alex Rodriguez, Troy Tulowitzki and Hanley Ramirez. Many talent evaluators expect that Seager is eventually bound for third base, but for the foreseeable future, he's staying put at short. He has the arm and hands for the position, but his range and quickness could be the limiting factors there.

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Though Seager's numbers at Double A Tulsa and Triple A Oklahoma City (.293/.344/.487 with 18 homers) don't jump off the page, scouts love his offense, putting a 70 grade (plus-plus) on his hit tool and a 60 (plus) on his power. As BP's Chris Crawford writes, "His ability to keep his hands in while still generating extension with above-average bat speed gives him a legitimate chance of winning batting championships … then consider that he’s likely to stick at a premium position. This is the type of player who wins MVPs." Whew. Beyond the tools is an approach at the plate that's well beyond his years in terms of pitch recognition and adjustments; many a commentator watching his play down the stretch noted his ability to slow the game down, allowing his skills and instincts to come to the fore.

The Dodgers let Rollins depart via free agency this winter and aren't even pretending that Seager’s status as the Opening Day shortstop is in doubt, so expect to see plenty of him this year.

Tyler Glasnow, RHP, Pirates

BA: 14; BP; 11, ESPN: 6, MLB: 10 (Average: 10.3)

A fifth-round 2011 pick out of a California high school, this 6'8", 225-pound righty lost a month of his 2015 season due to a sprained ankle suffered while running the bases for Double A Altoona. Including a rehab assignment at Class A, he split his season between three stops and drew some consideration for a late-season call-up. In 109 1/3 innings, he yielded just three homers, posting a 2.39 ERA and 11.2 strikeouts per nine. Coming on the heels of a strong season in high A ball in 2014, that's helped Glasnow leapfrog 2010 No. 2 pick Jameson Taillon (who has missed two full seasons due to Tommy John surgery) as the next big Pittsburgh pitching prospect.

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​Glasnow has ace-caliber stuff, starting with a fastball that sits at 93–96 mph, can graze triple digits (not unlike future teammate Gerrit Cole) and generates swings and misses both inside and outside the strike zone. He also offers a plus power curve and a changeup that's somewhere between a work in progress (ESPN’s Keith Law called it "a batting practice fastball" at the moment) and an average-caliber pitch. His height gives his pitches great depth, but those long levers are tough to get in sync, making his ability to repeat his delivery and thus his command a bit questionable at the moment; as Crawford noted, "[T]here are still fits of erratic control, and he misses in the zone more than you’d like for a top-of-the-rotation guy."

With just 53 innings at Triple A Indianapolis (including two postseason starts), Glasnow isn't expected to start the season in the big club's rotation. Instead, he'll work on fine-tuning his changeup and controlling the running game at Indy. Behind Cole and Francisco Liriano, the Bucs have a trio of pitchers—Jon Niese, Ryan Vogelsong and Jeff Locke—whose grips on rotation spots aren't exactly firm, so Glasnow's call-up could be sooner rather than later.

Orlando Arcia, SS, Brewers 

BA: 8; BP: 12; ESPN: 10; MLB: 10 (Average: 10.0)

The younger brother of Twins outfielder Oswaldo Arcia by more than three years, this 21-year old Venezuela native is by far the better player. Scouts consider the 6-foot, 165-pounder to be one of the best defensive shortstop prospects in baseball, with writing, "His soft hands, excellent range and strong arm could make him a Gold Glove-caliber shortstop early in his career, and there aren't enough good things that can be said about his instincts and overall feel for the position." Those sentiments are echoed in other evaluations.

Beyond Arcia's glove work, he's coming off a breakout season with the bat—.307/.347/.453 with 25 steals and eight homers at Double A Biloxi—thanks to quicker adjustments and increased use of his lower body. He's a contact-oriented line drive hitter with gap power, though as Law noted, [H]e's still hit first, ask questions later"—an observation backed up by his 5.4% walk rate. He's got the plus speed to make him a legitimate base-stealing threat, and if he can solidify his ability to get on base with consistency, he'll be a top-of-the-lineup hitter.

The Brewers traded incumbent shortstop Jean Segura to the Diamondbacks in late January and at the moment have utility man Jonathan Villar penciled in as their starter. They're in full-on rebuilding mode, and Arcia has no experience above Double A, so there's almost no chance he breaks camp with the big club. More likely, he'll start at Triple A Colorado Springs and reach the majors once the Super Two cutoff date passes in late May or June.

Trea Turner, SS, Nationals 

BA: 9; BP: 13; ESPN: 28; MLB: 11 (Average: 15.3) 

The 13th pick out of North Carolina State in 2014, Turner already has a rule informally named after him, as he was traded from the Padres to the Nationals in December of that year (officially as the player to be named later) but could not join his new organization until mid-June, once the 2015 amateur draft had passed. The so-called "Trea Turner Rule" now allows recently-drafted players to be dealt after that year's World Series.

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Turner, who's listed at 6'1" and 175 pounds, hit a combined .322/.370/.458 with eight homers and 29 steals at three minor league stops (two in Double A, plus Triple A Syracuse) before joining the Nationals in late August. With Washington, he went 9 for 40 with a homer and a pair of steals in 27 games, of which only eight were starts. He's a leadoff hitter in the making thanks to plus-plus speed ( graded him at the maximum 80 last year but has dialed that down to 75 this time around) and patience as well as a plus hit tool. He's refined his mechanics to drive the ball to all fields with more consistency, though his long swing generates concerns, and some evaluators doubt whether his power will even manifest itself in double-digit home run totals. Defensively, he's got the arm, range and hands to stick as a first-division shortstop.

Turner should be the Nationals' Opening Day shortstop, but the team has put obstacles in his path in the form of both holdover Danny Espinosa and newcomer Stephen Drew. Aside from the ability to jerk one out of the park now and again (13 homers for Espinosa last year, 17 for Drew), neither offers anything that Turner can't give them right now, but the Nationals are hedging to the point that it wouldn't be a surprise if he opens the year in Syracuse. If that’s the case, bet on Turner to be in a Nationals uniform well ahead of the team's even-more-highly rated righty, Lucas Giolito, who has just eight starts at Double A under his belt.

Steven Matz, LHP, Mets 

BA: 13; BP: 9; ESPN: 37; MLB: 15 (Average: 18.5)

Matz wasn't supposed to make this list. The Long Island lefty, a second-round 2009 pick, debuted for the Mets last June 28, but a strained latissimus dorsi suffered just two starts into his big-league career shelved him for two months. Nonetheless, he made a solid return in September and was part of the team's postseason rotation, albeit on a short leash. Including his October action, he posted a 2.68 ERA with 8.4 strikeouts per nine in 50 1/3 innings over nine starts. While he may rank behind Matt Harvey, Noah Syndergaard and Jacob deGrom (however you stack them) in the Mets' pecking order, that only points to the team's embarrassment of rotation riches.

Depending upon your prospect guru of choice, the 6'2", 200-pound Matz offers two or three pitches that grade out at least as plusses, starting with a 92–96 mph fastball that can go higher. His changeup is a plus or at least flashes plus as an out pitch that lacks only a bit of consistency. His curve "was the party piece when he was drafted and it has turned into an out pitch, featuring sharp 1–7 break that he can spot in the zone or bury to put away hitters" (per Crawford), and he's lately started to work with the so-called "Warthen Slider." Taught by Mets pitching coach Dan Warthen, the harder-than-average breaking pitch has been a difference-maker for his rotation mates.

While Matz's mechanics are sound, the knock on him thus far has been health. Between Tommy John surgery, the strained lat, shoulder tendinitis and knee and back issues, he's had so many setbacks that last year's 141 innings represented a high for his four professional seasons. He's got a rotation spot awaiting him out of the gate, but you can expect the Mets to monitor his innings and pitch counts in order to preserve his availability into the postseason, albeit at a much lower volume level than the noise surrounding Harvey last year.