LL’s Top 50 Mariners Prospects 2019: 28-27

It’s prospect list season and this year LL is doing our own in-house rankings of the top 50 prospects in the organization. You can find further explanation and our methodology at the hub for the series. The whole list so far is there, but if you missed any, here are links to 50-47, 46-43, 42-39, 38-35, and 34-31. Yesterday we started in on the Top 30, where we’ll be shifting to longer profiles of just two players a day as we get into players who are a little more well-known, whether because they’ve been written about elsewhere (or here, in the past) or have gained more exposure at higher levels of the minors. Today’s prospects are one name that should be familiar to fans who even casually follow the draft, and one young up-and-comer who might be new to you.

On the heels of a strong professional debut in the Dominican Summer League in 2017, Arias (say his first name like Die-yay-son or Die-Jason, which also helps in remembering how to spell it) emerged as one of the most intriguing pop-up prospects in the system as he made his way stateside in 2018. Pitching in the DSL, he showed a knack for collecting strikeout victims, posting 11.2 K/9 as he quietly slashed 3.41/2.57/2.43 for what was a 30-40 ballclub. His success wasn’t without question marks, however, as he was a touch old for the league at 21.

As it turns out, upper-90’s heat and an ability to dictate where it’s going pretty much plays anywhere and the flamethrowing San Cristobal, Dominican Republic-native had no qualms in dealing with same-aged players last season. He ended up logging 32.0 innings for the short season Everett AquaSox, overpowering Northwest League hitters to the tune of 12.7 K/9 while surrendering just 2.8 BB/9. He also comes at hitters with a low-80’s slider and change that do more to throw off the opposition’s timing than move their eye level.

Currently the fastball is Arias’s calling card, though, and he shows an ability to command it all around the plate with good sink. He broke a lot of bats this summer and induced some weak contact and ugly swings.

Arias comes at hitters with some quick deception and a whippy arm movement that may remind you somewhat of our dearly departed Edwin Diaz:

Statistical analysis on low level minor leaguers can be tough due to their often limited sample sizes—Arias is no exception—but one noteworthy trend for the right-hander was an extreme change in his ground ball and fly ball tendencies.

Arias will be stretched out a little further in 2019, which should shed a little more light on what type of pitcher he projects to be long term, but it appears the strikeouts are here to stay. -BT

Less than three years ago, the Mariners showed a ton of faith in Joe Rizzo. Not only did the M’s take him in the 2nd round, they signed him for an above-slot $1.75m bonus.

Rizzo was plucked out of Oakton High School in Virginia almost solely on the strength of his bat. His bat speed and ability to hit to all fields seemed like it would play at any position on the diamond, and although he was seen as a bit undersized, many felt he’d make enough contact that he could be a big-league regular.

In 2.5 minor league seasons, however, Rizzo has yet to show the strong bat that had draft evaluators so high on him. He showed good on-base skills in 2017, hitting .254/.354/.346 in Clinton at 19 years old. Sure, he didn’t hit for much power, with just 24 extra-base hits in 110 games, but it’s not uncommon for prospects to grow into their power (Mookie Betts would like a word), and the famously-chilly Midwest League isn’t exactly an offensive hotbed.

But after hitting just .241/.303/.321 in the hitter-friendly California League in 2018, it’s pedigree — not performance — that’s keeping Rizzo this high on our list. Four home runs over the course of the season is exceedingly low for the Cal League; for comparison, glove-first shortstop Kevin Santa had half that number in over a hundred fewer plate appearances. Man cannot live by dingers alone, but with less-than-plus speed, Rizzo’s skillset is maximized when he puts the ball over the fence, not into the corners. Should his hit tool surge to a 55 or 60 (above-average), and should his defense at the hot corner improve enough to keep him at third, it’s not too hard to imagine him as a fringe starter in a few years. Otherwise, given his lack of power and defensive versatility, he’ll struggle to find a fit in the bigs. Rizzo is still two months away from being able to legally have a drink, so there’s time for him to put it all together, but he’ll need to reverse the trend of his season this year, when he started out strong and faded down the stretch. -GB