Diaz signed with the A’s for $275K out of Colombia in 2016. Following a strong 2018 season in Rookie ball, the 19-year-old has spent the year with Short-Season Vermont, where he is slashing .264/.305/.442 with nine home runs and a K:BB ratio of 42:16 over 67 games. I have seen him multiple times throughout the summer.
Listed at 5-foot-10 and 175 pounds, Diaz possesses a stocky build without much room for physical projection. The young infielder generates above-average bat speed thanks to his strong wrists and forearms. His quick swing produces slightly above-average raw power, which he has accessed during games, a rare trait for teenagers. Additionally, Diaz does not sell out to tap into his natural pull-side pop, exhibiting an ability to hit to all fields. His above-average bat-to-ball skills led to an impressively low 15-percent strikeout rate. However, with the lack of strikeouts comes a lack of plate discipline, frequently swinging early in the count. This swing-happy approach is more a result of being overly aggressive within the zone rather than expanding it. With below-average speed, the 19-year-old does not contribute much value on the bases. However, his lack of foot speed does not hinder his ability at the hot corner, where he showcased soft hands and plenty of arm strength.
The combination of youth and production makes Diaz an intriguing prospect. Due to his aggressive hitting style, he will likely never be a high-OBP guy. However, the youngster’s ability to be more selective with pitches inside the strike zone will largely determine his future role. With his combination of contact skills, raw power and defense at third, I am a believer that Diaz will reign in his swing-happy approach enough to be a potential 2nd Division regular, FV 45.