SCOTTSDALE, Ariz. -- Isan Diaz has faced and overcome multiple challenges this year. Coming off an MVP season in the Rookie-level Pioneer League, he switched organizations shortly before he was set to report to Spring Training, going from the D-backs to the Brewers in a trade for Jean Segura. He struggled to stay above the Mendoza Line in his first two months in the low Class A Midwest League before rallying to the lead the circuit with 20 homers as a 20-year-old.
So facing perhaps the hardest-throwing pitcher he's ever faced Friday night wasn't going to faze Diaz. Squaring off against Surprise Saguaros right-hander Michael Kopech (Red Sox's No. 5), Diaz lined a 98-mph fastball for an opposite-field single to left field in the first inning and flared a 99-mph heater to center that he hustled into a double in the third. The Brewers' No. 8 prospect came around to score after the latter hit, the first run for the Salt River Rafters in an eventual 3-2 Arizona Fall League victory.
"It was cool," Diaz said. "I was just locked in. I heard this guy throws 100 and I just tried to slow it down and get the barrel on the ball. He's the one bringing all of the velocity, so you've just got to put the barrel on the ball."
Diaz, who went 2-for-5 to improve his average to .227 with three extra-base hits in five AFL games, excels at putting the barrel on the ball. He has impressive bat speed from the left side of the plate and surprising power for a 5-foot-10 middle infielder. He has seen action at both shortstop and second base in the Minors and for the Saguaros, and his fringy speed makes it more likely that he'll wind up at second in the long run.
Born in Puerto Rico, Diaz was a supplemental second-round pick out of a Massachusetts high school in 2014. He broke out as a prospect by batting .360/.436/.640 in the Pioneer League in 2015, topping the circuit in slugging, doubles (25), extra-base hits (44) and total bases (174). He overcame a slow start this year to finish at .264/.358/.469 and lead the MWL in homers, extra-base hits (59) and total bases (238).
"It was all mental," Diaz said of the adjustments he made to hit .296/.404/.569 in the second half of this season. "I just tried to go back to how I was thinking when I was in the Pioneer League. I went away from that at the start of the season, and the new organization kind of trickled in a little bit. Once I got into a groove, everything fell into place."
Kopech's first AFL outing was the most electric of the early season, as he struck out five in three hitless innings last Saturday while working with a 96-99 mph fastball and flashing plus secondary pitches. He averaged 98 mph with his fastball and reached 100 mph with five straight heaters in the second inning on Friday, but the Rafters made repeated hard contact against him. They touched him for seven hits and two runs in three innings, and they would have scored more runs if not for some baserunning miscues.