The Mets down have the deepest system but there are some potential impact players bubbling up to the surface, as well as some intriguing sleepers.
1. Peter Alonso | 1B | AAA —> After flashing his potential in 2017, Alonso fully broke out this past season. He split the year between double-A and triple-A while mashing 36 homers. He also walked 76 times in 132 games (along with 128 Ks). The swing-and-miss tendencies will impact his ability to hit for average but he’s also still growing as a hitter and has shown the ability to make adjustments. He’s not overly athletic or quick so he may never be better than average at first base but the power should give him the ability to be an impact hitter.
2. Jarred Kelenic | OF | R —> Kelenic has a good plan at the plate, as well as a controlled, short swing that is quick to the ball. He also appears willing to use the whole field at times. A 2018 first rounder out of high school, he acclimatized quickly to pro ball and is said to have great makeup, which should help him get full value out of his tools. I’m not sold on his power potential but he could hit for average, get a healthy number of walks, steal bases and play above-average defence.
3. Andres Gimenez | SS | AA —> Previously a glove-first player, Gimenez started to show more potential with the bat in 2018 while reaching double-A. He doesn’t have the best approach at the plate (His BB-K leaves something to be desired) but he has natural athleticism that allows him to succeed and he’s starting to grow into more pop, too. There is more gap-pop than over-the-fence power but he could hit 30 doubles, steal 20+bases and play excellent defence at short in his prime.
4. David Peterson | LHP | A+ —> For me, Peterson has mid-rotation potential due to possessing three average-or-better offerings, excellent ground-ball rates (He allowed just two homers all year) and above-average control. His command is still inconsistent but he also has a big frame to keep in sync. He’ll likely open 2019 in double-A and has an outside shot at making his MLB debut later in the year.
5. Mark Vientos | 3B | R —> Vientos had success in 2018 despite playing the full year at the age of 18. He showed the ability to hit for both average and power while controlling the strike zone well for his age and taking a healthy number of walks. He has 20+ homer potential and is hitting more balls in the air. He doesn’t have great athleticism in the field but possesses a strong arm for third base.
6. Ronny Mauricio | SS | R —> Mauricio received a $2.1 million investment in 2017 and had an excellent showing in his debut this season. He’s an overly-aggressive hitter but he has the potential to develop into a power-hitting middle infielder with strong defensive potential. He might have the highest ceiling in the system but is also still quite raw at 17. He’ll likely need another year in extended spring training with an eye towards full-season ball in 2020.
7. Justin Dunn | RHP | AA —> I’m not as big on Dunn as some. He’s not a huge guy and he already looks like he might be adding on some bad weight, that could be impacting his athleticism. He also slows his arm down and slightly alters his delivery when throwing his off-speed offerings. When his fastball and slider are working in tandem with a consistent arm slot he can overpower. He hasn’t been starting for that long so he deserves some more time to iron out the wrinkles but I think he’s best suited to relief work.
8. Anthony Kay | LHP | A+ —> Kay had solid results in 2018 after missing the ’17 season due to Tommy John surgery. However, his ceiling is modest as a future No. 4 starter. He has a solid fastball-changeup combo but the breaking ball is lacking (and the lost development time hasn’t helped). He’s also not the biggest pitcher so durability may always be a concern.
9. Thomas Szapucki | LHP | INJ —> Szapucki, 22, has lost significant development time due to injuries over the past two years, including Tommy John surgery which wiped out his 2018 season. He has the potential to be a mid-rotation arm if he can stay healthy. He has a mid-90s heater and excellent curveball. There was potential in the changeup, too, before he got hurt. He is a high-risk, high-reward player.
10. Franklyn Kilome | RHP | AA —> Kilome looks like a beast on the mound, standing 6-6 with upper-90s heat. But he’s also not overly athletic and has some effort with his wandering arm slot. Those issues limit the effectiveness of his stuff and he doesn’t consistently dominate. He has an average breaking ball but little-to-no changeup so I see a future in the pen. But he could be a dominant reliever.
Gavin Cecchini | SS | AAA —> Cecchini doesn’t have a huge ceiling but his value is derived from his defensive contributions. He handles himself at the plate ok and doesn’t strike out too much, while taking some walks. Unfortunately, he doesn’t hit with much authority nor does he run much leaving him as a singles hitter with the odd extra base knock. There is utility player upside here.
Shervyen Newton | SS | R —> Newton is my pick for the top-rising prospect for the Mets in 2019 — especially if he makes a full-season roster at the start of the year. A native of the Netherlands, he has developed quickly and has a body that hints towards massive power potential down the road. And he’s starting to learn to put more balls into the air, which helped him produce a solid number of extra base hits in 2018. He also takes a massive number of walks but has too much swing-and-miss to his game right now.
Tomas Nido | C | AAA —> Nido, 24, likely doesn’t have the offensive potential to be an everyday catcher but his defensive skills, including solid game calling and receiving, could make him a very good part-time contributor. He has some gap pop but his poor BB-K rates limit his overall ceiling.
Marc Hulet has been writing at FanGraphs since 2008. His work focuses on prospects and fantasy. Follow him on Twitter @marchulet.