Each 2015 MLB Playoff Contender's Most Undervalued Impact Player

Unlike other sports, unheralded players are often the reason why MLB teams have success in the postseason. Players like Brandon Belt and Jon Jay reinforced that theory during the 2014 playoffs. 

Over the next few slides, we'll identify a player on every MLB contender who has underrated impact potential. 

There's a healthy mix of young talent and veterans on this list. Michael Taylor, Eddie Rosario and Kolten Wong represent a new wave of talent ready to make noise in the postseason, while Justin Turner, Carlos Beltran and Kendrys Morales are quietly having memorable seasons later in their careers. 

Let us know what you think about our selections. Which other players on MLB contenders can make an impact this postseason? Which player on this list will be the most important asset this October? 

Without further ado, here's our list of the most underrated impact players on each MLB contender.

2015 Stats: .254/.352/.435, 17 HR, 90 R, 41 RBI, 17 SB, .787 OPS

Hidden behind the immense shadows of Jake Arrieta, Jon Lester, Kris Bryant and Anthony Rizzo has been the play of Dexter Fowler.

The Chicago Cubs outfielder is putting together a fantastic season in a rather under-the-radar way. Fowler is only hitting .254, but he's been able to reach base at a consistent clip. He's also on pace to record the first 20/20 season of his career.

One of Fowler's most important assets is his ability to draw walks. His 12.3 walk rate in 2015 is right around his career average and has helped mask a 22.2 strikeout percentage. Fowler sees plenty of pitches, as he ranks 13th in MLB in swing percentage. 

Fowler can affect a game with his plate discipline, power and speed. He's a nice fit ahead of Bryant and Rizzo at the top of the Chicago lineup and will burn opposing pitchers if they don't respect his ability.

2015 Stats: 5-2, 60.1 IP, 1.34 ERA, 8.65 K/9, 2.83 BB/9, .152 AVG

The Houston Astros have risen to the top of the AL West for a variety of different reasons, but an improved bullpen is the biggest reason why. Last season, the Astros ranked last in reliever ERA. In 2015, Houston's improved to No. 5.

Free-agent acquisitions Luke Gregerson and Pat Neshek have been key additions, but no Houston reliever has been as important as Will Harris. 

Harris has a 1.34 ERA in 60.1 innings this season. He leads the team in innings pitched and is tied for second in appearances. The right-hander has struck out over 25 percent of the batters he's faced, but his biggest strength is creating ground-ball contact. Harris induces grounders over 50 percent of the time. 

Houston has the quality bullpen necessary to be serious contenders in October. Harris will be in the center of that, even if most casual MLB fans don't know his name.

2015 Stats: .292/.355/.474, 17 HR, 64 R, 100 RBI, .829 OPS 

After a horrible 2014 season, heads were shaking when the Kansas City Royals inked Kendrys Morales to a two-year, $17 million deal this winter.

But not only has Morales returned to his previous best, he's also become one of Kansas City's most important offensive players.

Morales is hitting for both average and power with the Royals. He leads the team in RBI and is second in homers. In fact, Morales ranks fourth in MLB in RBI. 

The 32-year-old has regained his offensive prowess by using the entire field once again this season. Last year, Morales pulled the ball over 42 percent of the time. That total is down to 39.3 percent this season, while he's hitting the ball up the middle or the other way over 60 percent of the time. 

Kansas City introduced the baseball world to its plethora of young talent during 2014's fairy-tale run to the World Series. But it's the free-agent veteran Morales who's become the key run producer for the AL's best team.

2015 Stats: .268/.324/.441, 22 HR, 69 R, 71 RBI, .765 OPS

The Los Angeles Angels are barely over .500, but the club remains in the thick of the AL wild-card race with just four weeks left to play. 

When talking about L.A., the conversation starts and ends with Mike Trout and Albert Pujols. Both players are instrumental to any success the Angels have offensively. 

But one can add outfielder Kole Calhoun to that list as well. Calhoun enjoyed a 17-homer, 90-run season in a breakout year in 2014, and he has continued that good play in 2015. The 27-year-old has exceeded last season's totals in homers and RBI. 

After leading MLB last season in runs scored, the Angels rank 22nd in 2015. Trout and Pujols can't do it all, which makes Calhoun one of L.A.'s most important players.

2015 Stats: .290/.358/.500, 15 HR, 47 R, 52 RBI, .858 OPS

On a team with Adrian Gonzalez, Yasiel Puig and Howie Kendrick, who could have predicted that Justin Turner would lead the Los Angeles Dodgers in WAR? 

Maybe we should have seen this coming. The writing was on the wall last season when Turner hit .340 in 109 games for L.A. As a full-time starter this season, Turner has an on-base percentage near .360 and is slugging .500. He's also already posted career highs in homers and RBI. 

Turner has seen these improvements due to an ability to stay away from soft contact. The 30-year-old has the 11th-lowest percentage in baseball. Not only does Turner give himself a chance every time he puts the ball in play, but he swings at the right pitches as well—70.6 percent of his swings are on balls in the strike zone.

The Dodgers have plenty of storylines worth following over the coming weeks. Turner may not top the list, but his importance to Los Angeles can't be understated.

2015 Stats: .270/.289/.447, 9 HR, 47 R, 39 RBI, 10 SB, .736 OPS

For an organization filled with young talent, the Minnesota Twins couldn't have expected Eddie Rosario to become such an important piece of the puzzle this early in his career. 

But Rosario's well-rounded skill set has translated well at the major league level. The 23-year-old has hit nine homers, swiped 10 bags and played exceptional defense this season. Rosario almost never walks and whiffs quite a bit, but his power and speed offset those weaknesses enough to keep him in the lineup. 

As a defender, Rosario has a chance to be elite. He's accumulated 11 defensive runs saved this season. In significantly less innings, Rosario ranks ninth among MLB outfielders in that category. 

As the Twins continue to battle for a spot in the AL playoffs, the team will ask Rosario to play a key role. Whether it's with the long ball, stolen base or jaw-dropping defensive play, he has the potential to change any game he's playing in.

2015 Stats: .288/.366/.547, 10 HR, 28 R, 36 RBI, .913 OPS 

Entering 2015, Travis d'Arnaud was a highly touted prospect whose career had yet to take off. Despite playing in only 47 games due to injury this season, the New York Mets catcher has established himself as an important factor in the club's postseason chances. 

D'Arnaud has flashed the average and power that had many scouts drooling during his developmental years. The 26-year-old has gone deep 10 times this season, posting an on-base percentage over .360 in the process. 

One of d'Arnaud's biggest strengths is his plate discipline. He's only struck out 16 percent of the time this season, which has been coupled with a walk rate right around 10 percent. He doesn't normally chase pitches outside of the zone and puts the ball in play when he does take the bat off of his shoulder. 

The Mets have plenty of eyeballs on their young pitching, a revamped lineup and the return of David Wright. But if he's healthy, d'Arnaud's offensive capabilities take the New York lineup to another level.

2015 Stats: .277/.340/.473, 14 HR, 44 R, 50 RBI, .812 OPS

Carlos Beltran has enjoyed a fantastic career, but he saw a dramatic dip in production in an injury-filled 2014. 

But Beltran has rebounded this season to put together a quality season for the Yankees. The 38-year-old has improved his average, on-base percentage, slugging percentage and RBI totals from last season. 

In 2014, Beltran relied heavily on pulling the ball. His 51.5 pull percentage was his highest mark since 2008. Beltran has significantly lowered that total this season by utilizing the middle of the field once again. Because of that, his soft-contact percentage has fallen from 18.3 to 12.8 percent.

Beltran is a career .333 hitter in the postseason, which has to be luxurious for the Yankees. He may not receive the same attention as Alex Rodriguez, Mark Teixeira or Brian McCann, but he's still a potent bat capable of carrying New York in the playoffs.

2015 Stats: .281/.330/.441, 16 HR, 75 R, 68 RBI, 26 SB, .771 OPS

Players with unique blends of ability are always candidates to break out in the postseason. Don't be shocked to see Pittsburgh Pirates outfielder Starling Marte take on that status this October. 

Marte can do everything on the diamond. He's hitting .281 with 16 homers and 26 steals. He's capable of driving in runs or creating them, depending on the situation. Marte is prone to the strikeout, but there's not many more explosive offensive players in the game. 

The 26-year-old is also an elite defender. Marte's 19 defensive runs saved are good for the fourth-highest total among major league outfielders. He also ranks sixth in outfield assists with 12. 

Marte has a rare collection of talents that make him extremely valuable to the Pirates. He has his flaws and is often overshadowed by the great Andrew McCutchen, but he's in a position to announce himself to the rest of the baseball world over the next two months.

2015 Stats: .264/.325/.391, 11 HR, 64 R, 55 RBI, 15 SB, .716 OPS

Kolten Wong enjoyed some big moments in the 2014 postseason, but people still underrate him as the St. Louis Cardinals steamroll toward October. 

While that may not be a wise thought process, it's understandable. Wong is slashing a modest .264/.325/.391 on the year and hasn't posted the breakout numbers many expected entering the season.

But despite a mediocre campaign, Wong remains one of the most dangerous hitters in the St. Louis lineup. When he gets hot, Wong can affect the game with his power or with his legs. He's also a capable defender up the middle for the Redbirds. 

The St. Louis offense has its weak points, which makes Wong a critical component come the postseason. The Cardinals need his bat to make up for the losses of Matt Adams and Matt Holliday in order to reach their full potential.

At 24, Wong's upside is off the charts. If he can harness it over the course of the next few months, opposing pitchers will try to avoid him in the postseason.

2015 Stats: 12-9, 165 IP, 3.16 ERA, 5.73 K/9, 3.33 BB/9, .252 AVG 

When the Texas Rangers traded for Yovani Gallardo in January, the move just made sense. The right-hander figured to give the Rangers rotation some much-needed depth for a potential playoff campaign. 

Instead, Gallardo has proven to be the most important pitcher on the Texas roster. He leads the Rangers in starts, ERA and WAR. 

Surprisingly, Gallardo has had success despite continuously shrinking strikeout numbers. The 29-year-old has combatted that decline by maintaining a near-50 percent ground-ball rate and allowing less hard contact. 

The addition of Cole Hamels addressed a glaring weakness on the Texas roster, but it's also taken some of the shine off Gallardo. But Gallardo's consistency behind Hamels will be a determining factor if the Rangers are to hold on to the second AL wild-card spot over the coming weeks.

2015 Stats: .267/.302/.378, 10 HR, 67 R, 46 RBI, 18 SB, .681 OPS

In terms of offensive ability, Toronto Blue Jays outfielder Kevin Pillar doesn't stand out. He has a little bit of pop and can steal a bag here or there, but he struggles to get on base at a consistent clip. 

But Pillar's offensive flaws haven't kept him off the field this season. Why? The 26-year-old is an elite defensive outfielder. Pillar ranks third among major league outfielders with 20 defensive runs saved. 

The beauty of Pillar's defensive ability is that Toronto doesn't need another offensive threat. But an elite defender on the best offense in baseball? That's the type of combination that can lead to special things in October.

Only a few players in MLB can match Pillar's ability to change a game with a spectacular catch. He's a perfect fit for Toronto and doesn't have to be productive offensively to alter the landscape of a playoff series.

2015 Stats: .242/.289/.394, 14 HR, 42 R, 60 RBI, 15 SB, .683 OPS 

Michael Taylor's roller-coaster rookie year with the Washington Nationals has had many peaks and valleys, but the highly touted youngster has the talent to explode in October. 

Taylor's sub-.300 on-base percentage is directly correlated to an alarmingly high strikeout rate. The 24-year-old is whiffing 31 percent of the time and is prone to chasing pitches outside of the strike zone.  

But Taylor isn't the first young player to be exposed by major league pitching. The difference with Taylor is what he does when he makes contact. Judging by his 14 homers and 30.3 hard-contact percentage, Taylor can change a game with one swing of the bat. 

Taylor also provides value defensively in the outfield. He's posted seven defensive runs saved across all three positions and has thrown out six baserunners attempting to take an extra base.

Washington still has work to do in order to earn a postseason berth, but the prospect of Taylor in October is intriguing. The raw ability is obviously there, so it's just a matter of putting it all together to create the total package. 

Stats courtesy of FanGraphs and accurate as of Sept. 8.