The hard-throwing Alcantara gave up one run on four hits while striking out Yoenis Cespedes twice. He was lifted after 32 pitches and did not allow a walk. The touted fastball velocity emerged, as he reached 98 mph four times. Even after he was replaced, Alcantara threw 27 more pitches in the bullpen.
"I was more emotional," Alcantara said. "They have a veteran lineup that I was going up against. I had to be more focused."
Ranked by MLB Pipeline as the Marlins' No. 3 prospect, Alcantara is in the mix for a rotation spot. Because of his age and inexperience, it's not guaranteed. The club is evaluating everything, and Alcantara still needs to polish up some things, like his offspeed pitches and fastball command.
A centerpiece in the trade to the Cardinals for Marcell Ozuna, Alcantara logged 8 1/3 innings of relief for St. Louis in 2017. The Marlins envision him as a front-line starter.
"It's exciting, because over with the Cardinals, it would have been a battle for me to make the rotation," Alcantara said. "Over here, I have more of an opportunity, and I have a greater chance of cracking the rotation."
Alcantara saw many of the Mets' regulars. In the first inning, he allowed a leadoff single to Asdrubal Cabrera. Jay Bruce delivered a double. Cabrera scored on Todd Frazier's RBI groundout to short.
"I knew they were going to come chasing after my fastball," Alcantara said. "I knew they were going to be ready to go off the fastball because that's what the scouting report said."
After throwing 96 mph in the first inning, Alcantara's fastball jumped to 98 mph in the second and third innings. But both of his strikeouts came on sliders, which he got Cespedes to chase for strike three twice.
"We like Sandy from the standpoint, he's really a composed kid, and calm and always willing to know there is room for growth," manager Don Mattingly said. "We talk about velocity. He's a guy who throws hard, but he has an understanding that as a starting pitcher, you've got to be able to do more than that."
Pitch location is equally important, and that was evident in the second inning. Alcantara delivered a 98-mph first-pitch fastball to Kevin Plawecki, who lined it to right for a single. But the inning ended one batter later, when Kevin Kaczmarski bounced into a double play.
In his first outing, two innings of relief against the Nationals, his fastball velocity reached 96 mph. As he builds up arm strength, his velocity is expected to increase, and he's routinely reached triple digits. His average four-seam fastball last year was 98.6 mph, according to Statcast™, and his two-seamer was 97.5 mph.
Opponents hit .167 off his four-seam fastball, which makes it even more tempting to keep bringing heat.
To secure a rotation spot, Alcantara must also show he can work both sides of the plate with his fastball and complement it with offspeed pitches. His slider averaged 85.6 mph, and he adds a changeup.
"You've got to be able to locate a little bit," Mattingly said. "You've got to use your secondary pitches. You need more weapons than just the one. Guys will hit anything, no matter how hard it is, if they don't really feel like you can do anything else."