Guillermo Heredia, Starting Center Fielder

With Jarrod Dyson set to be a free agent, and Leonys Martin both ineffective and DFA’d twice, there has been some uncertainty among Seattle Mariners fans regarding who will patrol center field for the team in 2018. Luckily for Mariners fans, they have an internal option who is potentially an above-average player already playing for their favorite team: Guillermo Heredia.

At 26, Heredia is a bit old to just be emerging. Though unlike other players his age, his late arrival to the major leagues has nothing to do with his ability. Heredia defected from Cuba in January of 2015, just a few weeks before his 24^th birthday. Before defecting, Baseball America ranked Heredia as the 11^th best prospect in Cuba. He was signed by the Mariners in February 2016, after sitting out the entire 2015 season.

Heredia, considered by most to be a glove-first prospect, started the year hot with the bat in AA Jackson, hitting .293/.405/.376 in 260 plate appearances while living up to his defensive reputation. Heredia walked more times (36) than he struck out (32) and earned a promotion to AAA Tacoma after just 58 games. Heredia’s 35 AAA games—where he hit .312/.378/.414—were split by a cup of coffee when the major league club. In AAA, Heredia improved his strikeout rate to 9.6%, while his walk rate fell to 7.5%, but his combination of solid on-base skills and great defense earned him a call up to the majors for good on August 22^nd.

Heredia made the most of his cup of coffee, hitting a solid .250/.349/.315, drawing 12 walks against just 15 strikeouts in a small sample of 107 plate appearances. Thanks to his strong on-base skills, and stellar defense, Heredia managed 0.4 WAR in just 45 games — with most of his playing time coming as a late-inning defensive replacement.

Despite his stellar defensive reputation, Heredia was relegated to corner outfield for all but one game of 2016 due to Leonys Martin’s stellar defense in center. Still, Heredia managed to make an impression. Heredia passed the eye test, and scored positively in both UZR/150 (+7.2) and DRS (+3). But what stood out most was his throwing arm. This throw made me a believer that among his many pretty good skills, he had at least one that was elite:

Petit out after challenge

He made an equally impressive throw this season to get George Springer trying to go from first to third, an out that proved pivotal in the Mariners securing a series win against the Astros:

Heredia nabs Springer at third

In just 705 innings in the outfield this season, Heredia has four outfield assists and +2.3 rating in the ARM component of UZR. His arm is an asset, and potentially one of the better throwing arms in the league.

Heredia’s scores in the range component of UZR were positive in 2016, and have been negative in 2017, for a total of -2.9 in 705 innings across three outfield positions. DRS is more favorable, giving him a +7 score across all three outfield positions, and exactly even at -1 in 251 innings in center. There’s no doubt he has the speed to play there, though his route efficiency is in question. Still, Heredia has nabbed 19 out-of-zone plays in center this season, and can outrun plenty of his poor jumps. Across all three outfield positions, he has scored +0.0 UZR, and +0.3 UZR/150. Even the most pessimistic evaluation of his defense would likely call him slightly below average in center.

If you’re someone that does hold the pessimistic outlook on his defense, then his bat would have to justify his playing time. The good news is Heredia now has a little more than two-thirds of a full season’s worth of plate appearances, and has steadily improved.

Heredia is hitting .271/.344/.368 (97 wRC+) in 450 career plate appearances, with a solid 14.5% strikeout rate, and decent 6.1% walk rate. He’s not riding an unsustainably high BABIP, either — his BABIP sits at .310, perfectly reasonable for someone with well above-average speed like Heredia.

In 34 games in the second half of 2017, Heredia has found a little more power: his first half ISO was just .091; it currently sits at .137 in the second half. Nine of his extra-base hits came in 208 plate appearances before the break, while 12 (11 doubles, 1 home run) have come after.

Even more encouraging is the fact that Heredia isn’t just a pull, or slap, hitter. Heredia’s career numbers split by where the ball is hit show that he can be effective hitting to any part of the field.

(Since walks aren’t put into play, this split is just AVG/SLG)

Pull: .333/.571
Center: .308/.342
Opposite: .323/.376

Essentially, Heredia only has power on his pull side, but can get on base hitting the ball in any direction.

There is one elephant in the room, though: despite his outstanding speed, Heredia just can’t steal bases. Perhaps he can learn how to get better jumps as he gains experience. It’s important to note that he missed his entire age-24 season trying to become eligible to sign with a team. But so far, Heredia has shown that he’s probably best utilizing his speed once the ball is put in play, rather than trying to advance via the steal. Between the minors and majors, Heredia has seven steals and has been caught 11 times.

Heredia can be an effective baserunner outside of when the ball is being pitched, though. He’s turned numerous singles into doubles by hustling out of the box, and shown that he can take two bases on a wild pitch If the catcher is lollygagging, as he did against Boston earlier this year:

Gamel scores on a wild pitch, ties the game

What the Mariners have in Heredia is a raw, speedy athlete with an absolute cannon for an arm, above-average on-base skills, and below-average, but developing, power. Heredia might never hit more than 10 home runs in a season. He might never steal more than 10 bases, either. But he’s amassed 1.2 WAR and posted a .344 OBP while playing at the very minimum passable defense in center field, with the upside for better.

He’s not Jarrod Dyson with the glove. He’s not Andrew McCutchen at the plate. What he is, though, is a competent offensive and defensive player with untapped potential. Even if he never improves, he looks capable of giving Seattle a 2-win center fielder going forward. Even a slight improvement could turn him into an above-average player, and one who is under team control for five more years.