SF Giants Prospects Rankings: 10 Who Just Missed The List

By Marc Delucchi
Scottsdale Stadium, the SF Giants Spring Training facility. (Photo by Christian Petersen/Getty Images)
Scottsdale Stadium, the SF Giants Spring Training facility. (Photo by Christian Petersen/Getty Images) /
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SF Giants, Melvin Adon, Prospects
SF Giants pitching prospect Melvin Adon during the 2018 Arizona Fall League All Star Game at Surprise Stadium. (Mark J. Rebilas-USA TODAY Sports) /

SF Giants Next 10 Prospect Rankings
36. Melvin Adon

Age: 26
Highest Level: Triple-A (Sacramento)
Acquired: IFA (2015)
Future-Value Grade: 35

Melvin Adon is a perfect example of why pitching prospects are so difficult to project. While he did not turn pro until well after most top international free-agent prospects, Adon has a true potential 80-grade fastball, routinely sitting from 97-100 mph and touching 102 mph. It isn’t straight either and has some run to make it even harder to square up.

He’s always flashed a slider that never was too well developed, but if it could turn into a strong enough second offering, he might have been able to be a succesfully big-league starter on those two pitches alone. However, at the very least, it was easy to project him as a closer.

As a starter, Adon never found the dominance, or the strikeout rates, that many expected and the Giants fully converted him to the bullpen last season. It caused the spike in strikeouts that scouts expected (11.8 K/9 at Double-A), but came with an inflated walk-rate (5.5 BB/9). Still, his stuff was clearly difficult for hitters to square up, and even with plenty of free passes, Adon managed a 2.60 ERA, 2.93 FIP, and 2.94 xFIP.

A late-season promotion to Triple-A only made things weirder. In 10.1 innings, Adon struck out 18, but walked 8, and allowed 16 earned runs. However, fielding independent stats were pretty high on his performance in the context of the Pacific Coast League (FIP of 3.89).

Frankly, it remains surprising not to see Adon make his big-league debut this season and it suggests his work in Spring Training or at the team’s alternate site stalled out. Without starter upside, Adon still retains a decent shot at becoming a lockdown closer, but even if his control can develop into a 40-grade tool, he could be a solid setup option.