The Seattle Mariners made it through the trade deadline without giving up any of their top prospects, leaving a promising farm system in place.

Seattle has high hopes for the likes of D.J. Peterson, Taijuan Walker and Chris Taylor to make big contributions in the major leagues for several years to come. New draftees Alex Jackson and Gareth Morgan also have strong potential, in addition to good pitching depth throughout the system.

With all that talent at the top of prospect rankings, the Mariners have several others who are currently flying under the radar. 

Four of these players stand out as being the best underrated prospects in the system and will soon start to receive more attention if their strong 2014 seasons continue.  

 

Patrick Kivlehan, 3B

Kivlehan moved up to No. 9 in MLB.com’s midseason rankings of the top Mariners prospects but is arguably having the best year of anyone in the minor league system.

After putting up strong numbers at High-A, Kivlehan has really started to shine in Double-A. Through 78 games with Jackson, Kivlehan has posted a .318/.401/.521 line with nine home runs.

In addition, Kivlehan’s plate approach has improved significantly in Double-A compared to previous levels. Kivlehan has a walk rate of 11.6 percent and a strikeout rate of 18.3 percent in what is typically considered a pitchers’ league.

As with many others before him, Kivlehan struggled for about 20 games with the transition from hitter-friendly High Desert. He has since found his stride, with 17 doubles over his last 56 games.

Kivlehan primarily played football during his college career at Rutgers and has a good combination of size and athleticism. He has plenty of untapped power potential and also stole 16 bases in 2013, although that number has dipped slightly this season.

That athletic potential was what prompted scouting director Tom McNamara to select Kivlehan in the fourth round of the 2012 draft, via Keith Sargeant of MyCentralJersey.com.

“What we saw with Kivlehan is he’s just a physical, athletic kid,” McNamara said. “The way we look at him is he played college football, he’s played against some of the best athletes in the country. And he just started to play baseball again, and he put up numbers.”

Kyle Seager will be manning third base in the majors for the foreseeable future, so Kivlehan will be in need of a position change. Kivlehan could move to first base should Peterson be promoted to Triple-A before him and has also recently seen time in left field.

Kivlehan remains the most underrated prospect in the organization, but that will change soon if he continues to put up numbers and is moved to Triple-A before the end of the year.

 

Austin Cousino, OF

Cousino was Seattle’s third-round selection in the 2014 draft back in June, behind Jackson and Morgan. While he is rated well behind those two in terms of potential, Cousino has impressed so far.

There’s no question that Cousino was drafted due to his defensive potential in center field. Cousino was a member of the SEC All-Defensive Team during all three seasons of his college career at Kentucky. 

Along with Gabriel Guerrero, Cousino has the strongest defensive outfield tools in the Seattle organization.

Cousino also has above-average speed and has already stolen 19 bases with Low-A Everett. The only uncertainty was if he would be able to hit enough to stick in the minors.

Through the first 45 games of his professional career, Cousino has posted a .303/.388/.469 line. Cousino will mostly use his quick bat speed to be a singles hitter, but he has hit five home runs and 12 doubles with Everett.

As a result, Cousino was selected to the Northwest League All-Star Game.

It’s still early in Cousino’s career, but that offensive production combined with terrific defense means he’s worth keeping an eye on. Cousino should be in line for a promotion to Mid-A Clinton shortly.

 

Matt Brazis, RP

While he is nearly 25 years old and just recently made his Double-A debut, Brazis has posted some eye-opening numbers at every level he’s stopped at.

Brazis missed significant time during his career at Boston College and was selected in the 28th round of the 2012 draft as a project with great raw stuff that would take some time to develop. That potential has been realized in 2014, as Brazis has posted some impressive command numbers.

In 23 games to begin the year at High Desert, Brazis posted a strikeout rate of 31.1 percent and a walk rate of just 5.0 percent. Brazis allowed just four home runs in 39.1 innings, a very impressive rate for the California League.

He’s since moved to Double-A, allowing two runs in 17.1 innings while striking out 16.

Brazis features a low-90s fastball plus a good curveball and slider. He has great control over all three pitches, as evidenced by his low walk rate at every professional level he’s been at.

Still, that doesn’t seem like a repertoire that would allow Brazis to post such big strikeout numbers. Farm director Chris Gwynn explained Brazis’ success back in 2012, via John Hickey of Baseball America.

It starts with the deception; it’s big-time deception.

When you have this kind of command, throwing the fastball at the knees both on the inside or outside corners, that makes everything else work. … The hitter has to look for the fastball, so the other pitches look better. And because he locates the ball as well as he does, the fastball is tough to hit.

Seattle’s bullpen is tough to crack at the moment, so it may be a while before Brazis gets his shot in the majors. The Mariners have successfully called up relievers directly from Double-A before, so Brazis could get a look next year if he continues to pitch well.

All Stats via FanGraphs.com unless otherwise noted.

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