SAN FRANCISCO -- Before Melvin Adon is ready to ascend to the Majors with his triple-digit fastball, the Giants must make sure they're ready for him.
Adon, 24, possesses a starter's durability and the potential to be a closer. It'll be up to San Francisco which ultimately suits him best.
"I think he can be great, no matter which role he's placed in," said Matt Yourkin, who has coached Adon since the Giants signed him as an undrafted free agent in 2015 and is Class A Advanced San Jose's pitching coach.
Adon, ranked as San Francisco's No. 19 prospect according to MLB Pipeline, thrilled the Giants with his Arizona Fall League performance this year. Working exclusively in relief for the Scottsdale Scorpions, he struck out 21 and walked three in 10 appearances spanning 12 1/3 innings. The right-hander allowed just seven hits.
"He's always had good stuff," Yourkin said. "It's just nice to see it come together and show the refinement that he has been working on."
Further work was necessary for Adon, who walked 34 batters in 77 2/3 innings over 16 appearances (15 starts) with a 4.87 ERA for San Jose. His dramatic improvement in his strikeout-to-walk ratio reflected his diligence in learning to command his slider, which complements a fastball that has reached as high as 102 mph.

Switching from starting during the regular season to relieving in the AFL helped Adon focus on improving incrementally. He was free to try to develop a single secondary pitch, not multiple deliveries as a starter would.
"Being in a bullpen role took the onus off of having to feel like he had to have a three- or four-pitch mix," said Matt Buschmann, an assistant director of player development for the Giants who recently joined a group of his counterparts to observe the AFL. They returned to San Francisco with the sense that Adon's bullpen aptitude "was really, really exciting to see."
The Giants are in no rush to determine Adon's future. His development and the pitching staff's evolution likely will make the decision for them.
"It's one of those great problems to have," Buschmann said.