MIAMI -- Sandy Alcantara possesses a 100-mph fastball, and he has top-of-the-rotation starter potential. With all the makings of a future ace in place, it would be tempting for the Marlins to speed up the developmental clock for the 22-year-old.
They're not. They're going to let their No. 1 prospect progress at his own speed.
To further acclimate to the next level, Alacantara recently participated in MLB's Rookie Career Development Program.
Alcantara has had a taste of pitching in the big leagues, making eight relief appearances as a September callup for the Cardinals last year. A native of the Dominican Republic, Alcantara is welcoming the fresh start ahead of him with Miami.
"For me, I think it's a big opportunity, because new doors are opening to keep moving forward and to keep competing hard like I've always done," the right-hander said.
Alcantara was one of the centerpieces of the December trade that sent All-Star outfielder Marcell Ozuna to the Cardinals. In return, the Marlins also received outfielder Magneuris Sierra, right-hander Zac Gallen and lefty Daniel Castano. According to MLB Pipeline, Sierra is now the Marlins' No. 5 prospect and Gallen is No. 15.

"I feel happy, because they've given me that responsibility to be there with them," Alcantara said. "I'm going to work hard and keep being humble. Also, for the guys coming in behind me, to help them to follow my advice and also follow in my footsteps."
Ability-wise, all the makings are there for the right-hander to be a standout. It's now a matter of experience and commanding his pitches.
Per Statcast™, Alcantara's four-seam fastball -- on 45 pitches tracked in the big leagues -- averaged 98.51 mph. The MLB average was 93.19 mph. His fastball spin rate average was 2,359.16 rpm, also roughly the league average (2,254.62 rpm).
In 8 1/3 big league innings, Alcantara had a 4.32 ERA, striking out 10 and walking six.
"All of these guys are considered prospects, because they haven't proven themselves at the Major League level yet," Marlins vice president of player development and scouting Gary Denbo said. "They all have things they need to work on. You can probably say that every one of the pitchers that we acquired need to work on their fastball command.
"They have to make sure they can locate fastballs where Major League hitters aren't going to be able to impact them. You can say the same thing about Sandy. That's our No. 1 objective with all of our pitchers, to make sure they have good command of their fastballs."
Alcantara had been with the Cardinals since 2014, and he's logged 369 Minor League innings. A year ago, he went 7-5 with a 4.31 ERA in 25 games (22 starts) at Double-A Springfield. In 125 1/3 innings, he struck out 106 and walked 54.
After being called up in September, Alcantara threw as many as two innings just once. But he gained valuable experience, working with All-Star catcher Yadier Molina and picking up advice from starters like Carlos Martinez.
"They helped me a lot to keep competing and just being there with them," Alcantara said. "I'm going to try to take the advice that guys like Carlos Martinez and Yadier Molina gave me to Spring Training, to be ready to compete for a spot at the Major League level with the Marlins."