MIAMI -- Sandy Alcantara officially came off the disabled list on Monday, but the rookie right-hander is not rejoining the Marlins' rotation just yet. The club optioned the 22-year-old to Triple-A New Orleans.
Before returning to the big leagues, the Marlins first want Alcantara to polish up his fastball command. Over the past month, he has been recovering from a right axillary infection.
"I don't think anybody was really happy with fastball command and what they've seen in the three outings he's had," Marlins manager Don Mattingly said. "That's one of the things we've kind of preached. We just felt like we wanted to let that progression keep going. Let him get into rhythm, let him get a hold of that, and see where we go from there."
Alcantara made his first big league start -- and Marlins debut -- on June 29, allowing one run in five innings with two strikeouts and five walks against the Mets. He went on the 10-day DL on July 4.

On the surface, Alcantara's three rehab appearances with Class A Advanced Jupiter were respectable -- 3.97 ERA in 11 1/3 innings with eight strikeouts and five walks. Beyond the numbers, Alcantara showed some rust by not consistently hitting his spots. In his last start on Friday against Palm Beach, the right-hander worked 4 2/3 scoreless innings, allowing two hits while walking three and striking out four. Of the 84 pitches he threw, 51 were strikes.
Also of note in that outing, Alcantara's fastball velocity topped at 95 mph, and his four-seam was mostly in the 93-94 mph range. In his second rehab start, his fastball reached 97 mph. Earlier this season at New Orleans, his fastball maxed in the 97-98 mph range.
"My second rehab start, I was able to get it up to 97," Alcantara said through an interpreter. "This last one I had, I was in the 94-95 range. I'm not sure what happened."
Alcantara threw a bullpen session on Monday at Marlins Park, and there is a sense he has subtracted some velocity to help find his spots better.
"There's absolutely no concerns with him health-wise," Mattingly said. "We do want him to be more aggressive with his four-seamer. That's something we've relayed to him. We wanted to see him throw that four-seamer where he wants."
Ranked as the Marlins' No. 2 prospect by MLB Pipeline, Alcantara opened the season at New Orleans, going 5-3 with a 3.71 ERA in 14 starts.
The Marlins acquired Alcantara from the Cardinals last December in the Marcell Ozuna trade.
Worth noting
• The Marlins promoted their first four picks taken in the 2018 MLB Draft. First-rounder Connor Scott, second-rounder Osiris Johnson and Competitive Balance Round B pick Will Banfield joined Class A Greensboro. Miami also promoted Tristan Pompey (third-rounder) and shortstop Jose Devers from Greensboro to Class A Advanced Jupiter. The Marlins acquired Devers, 18, in the Giancarlo Stanton trade with the Yankees.
• Lewis Brinson (right hip inflammation) anticipates playing before the season ends.
"Yes, I will," Brinson said. "Obviously, I want to finish strong. I was starting to pull some things together before I went on the DL. I'm definitely going to play again this year."
The rookie center fielder is progressing with his activities. He ran and took swings on the field on Monday.
"I'm good," Brinson said. "I'm running. Did some sprints. Nothing crazy yet. I hit on the field today. Everything feels good."
• Reliever Drew Rucinski (right groin strain) is scheduled to throw two innings -- or around 40 pitches -- in a rehab assignment with Jupiter on Tuesday.