JUPITER, Fla. -- Mentally and physically, Sandy Alcantara was ready for his first Grapefruit League start. Still, the result left the 24-year-old right-hander anything but satisfied.

Alcantara had a sloppy two innings, giving up two runs (one earned) on two hits with three walks, a balk and a strikeout. He even committed a throwing error amid Monday's 6-3 comeback win over the Cardinals at Roger Dean Chevrolet Stadium, which improved Miami to 3-0 in Spring Training for the first time since 2014.

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“I feel really bad about the day that I had today,” Alcantara said. “I don’t know why that happened to me. I have to keep working hard and keep getting better.”

Alcantara's fastball sat at 95 mph, instead of the 98 mph that the right-hander was expecting.

You don’t read too much into Spring Training performances -- especially this early in camp. But Alcantara was openly self-critical.

Alcantara made his first start Monday since his All-Star nod in 2019, when he had a 3.88 ERA in 32 starts (197 1/3 innings).

“There’s a difference to me when Sandy is picking at the zone,” Marlins manager Don Mattingly said. “But today, it looked like he was trying to attack the zone. He just didn’t have command today. The ball was running big for him.”

Alcantara is considered the club’s ace, regarded as Miami’s likely Opening Day starter. He’s hoping to build on what he accomplished a year ago.

The Marlins acquired Alcantara as part of the Marcell Ozuna trade with the Cardinals in December 2017.

On Monday, against his former organization, Alcantara struggled throwing in the zone, ultimately hurling 38 pitches, only 19 for strikes.

“My two-seam was not working today,” he said. “My breaking ball, too. I’ve got to keep getting better.

“I don’t want to walk anybody. But that happens in the game. You’re not going to be perfect all the time. Keep getting better every day. Keep working in my ‘pens and take advantage of my opportunities.”

Building Sixto back
A year ago, the Marlins had a customized pitching buildup program for top prospect Sixto Sanchez, and the results were positive. In 114 innings, the 21-year-old had a 2.76 ERA, including a 2.53 ERA in 103 innings at Double-A Jacksonville.

Since it worked before, the Marlins will once again build Sanchez up slowly for the regular season. So while many of Miami’s pitching prospects in big league camp are facing hitters -- either in Grapefruit League games or live batting practice -- Sanchez is easing his way into his throwing program.

“Sixto is pretty much on the same program as last year,” Mattingly said. “We know where his innings limits are. He pitched career innings last year. We know where we want to go with it. We had a slower buildup with him last year. It was successful.”

Sanchez finished 2019 as the Marlins’ No. 1 prospect, per MLB Pipeline, and he was recently anointed the 22nd overall on their Top 100 Prospects list.

“Sixto’s program is kind of Sixto’s program,” Mattingly said.

By comparison, Edward Cabrera, Miami's No. 6 prospect a year ago, has impressed against hitters in live batting practice.

“Cabrera’s program is kind of Cabrera’s program,” Mattingly said. “So there is no cookie-cutter program. But with Sixto, we’ve had success. He’s healthy. He’s stayed healthy. Our job is to make sure he stays healthy again. As I said early on, we’re going to get him ready for the season. That’s our main goal.”

No no-no
The Marlins were held without a hit until a five-run seventh inning, when the rally was started by outfield prospect Brian Miller's triple.

Miller, the Marlins’ No. 25 prospect a year ago, was the 36th overall pick in 2017. Mattingly called him “interesting,” and noted that he is the type of under-the-radar prospect who does a lot of things well.

JJ Bleday, the No. 29 prospect in baseball, added the game-tying RBI single in the big inning.

Anderson all good
There were some anxious moments after third baseman Brian Anderson was struck by a pitch on his left hand in the fourth inning and replaced by a pinch-runner.

Anderson broke the same hand after being struck by a pitch last August. He said he is fine, and a big reason is the fastball by Ryan Helsley deflected off a protective padding that Anderson is now wearing on top of his batting glove.

Up next
The Marlins take to the road to face the Astros at West Palm Beach, Fla., on Tuesday at 1:05 p.m. ET. José Ureña will get the start for Miami, and hard-throwing prospects Jorge Guzman and Jordan Holloway are also slated to pitch. Catch the action live on MLB.TV, or listen on Gameday Audio.