SAN FRANCISCO - OCTOBER 26: San Francisco Giants manager Bruce Bochy adjusts his hat as he speaks to reporters at AT&T Park on October 26, 2010 in San Francisco, California. The San Francisco Giants will face the Texas Rangers in the first game of the World Series on Wednesday at AT&T Park. (Photo by Justin Sullivan/Getty Images)

Melvin Adon‘s professional career has been a roller coaster. However, he is beginning to turn some heads in the Arizona Fall League (AFL), and that could be good news for the San Francisco Giants.

Adon signed with the San Francisco Giants for $50,000 as an international free agent in 2015. He was 20-years-old then, so he was a little older than many of the International free agents.

Adon features a power fastball, and he can maintain high velocity for multiple innings. His fastball is exactly what is capturing everyone’s attention:

Took a month to get it, but the first member of the triple digit club on the new @BaseballCensus Stalker Pro II is #SFGiants RHP Melvin Adon. pic.twitter.com/GyJxO4P6yf — Bobby DeMuro (@BobbyDeMuro) October 23, 2018

With a pitcher who can throw that hard, you would expect the results to match the ability, right? Well, it gets a little tricky. Adon has worked out as a starting pitcher for much of his career, and the results have been mixed at best.

For his career, Adon has posted a 4.36 ERA. This includes 62 starts and 7 relief appearances. He has allowed over one hit per inning and has struggled with his command as evidenced by his 3.6 BB/9 ratio.

Despite throwing a 100 MPH fastball, Adon seems to struggle with getting hitters out. His secondary pitches include a change-up and slider. These offerings are not of the same quality as his fastball. However, there is some good news:

When #Giants Mel Adon is good, he’s pretty damn good. Had the SL tonight which matters more to me than the gas, prodigious per usual — John T Eshleman (@2080_John) October 23, 2018

Clearly, Adon has impressed scouts in the Arizona Fall League. In 6.1 innings of work, he has posted a 1.42 ERA with 13 strikeouts and 0 walks. That last stat is an important detail as Adon has demonstrated improved command as a reliever.

Becoming a relief pitcher might be the next step in Adon’s development. Unfortunately, Adon only has seven relief appearances outside of the AFL to his name. As a result, it is difficult to draw conclusions from his performance as a reliever due to the small sample.

However, Adon’s ability to further develop his slider as a compliment to his fastball will go a long way. Adon is eligible for the Rule 5 Draft this winter, so the San Francisco Giants will have the opportunity to protect him from that draft by adding him to the 40-man roster.

Pitchers who throw hard like Adon are typically vulnerable from being plucked away. Given how he has performed in the AFL, it seems very possible that he could get picked in the Rule 5 Draft.

Adon’s performance is very important to the Giants. The Giants are likely using Adon’s AFL performance to determine if he is worth using a valuable 40-man roster spot on. So far, Adon has not disappointed.

Adon may have found a niche as a reliever. He has no problem maintaining velocity, and his performance in the AFL has been encouraging.

The only downside is there is not enough of a sample outside of his AFL stint as a reliever to draw any conclusions.

The San Francisco Giants will have to lean heavily on Adon’s performance this fall, but they have to like what they have seen so far.