Since coming to the New Orleans Zephyrs on May 21, pitcher Andrew Heaney, the No. 1 prospect in the Miami Marlins’ system, has lived up to expectations.

Heaney, a left-hander with good velocity and excellent placement, is 3-0 with a 2.74 earned-run average, with 27 strikeouts in 23 innings and just two walks since coming to the Zephyrs from Double-A Jacksonville. It has brought media reports that his call-up is imminent.

Heaney, the ninth overall pick in 2012 from Oklahoma State, was scratched from his scheduled start Wednesday in El Paso, Texas, further feuling speculation he’ll be called up. That came on the heels of Marlins pitcher Henderson Alvarez being injured Sunday, which first started reports that Heaney may be headed to Miami.

But Alvarez is OK.

Two sources with the organization said Heaney is just getting a rest.

“Counting spring training and Double-A (53.2 innings), he’s pitched a lot of innings,” one of the sources said. “They just want to pace him.”

However, it was in the Zephyrs’ last trip West, to Colorado Springs on June 1, that was Heaney’s only tough start since coming to the Zephyrs. He gave up six runs (five earned) on 11 hits and four walks, including a home run. New Orleans won 9-8, but he didn’t get the victory.

Heaney said late last week that he was looking forward to the trip, where high altitude and low humidity can make for a hitter’s paradise. He also was scheduled to pitch June 16 in Albuquerque, another high-altitude venue.

“I didn’t do too well the last time out there,” he said. “I left too many balls over the plate, didn’t put guys away. The things I got away with my first two starts, I didn’t get away with there.”

That was Heaney’s only blemish. In his first Triple-A start, on May 22 at Zephyr Field, he scattered seven hits over five innings, allowing one run with seven strikeouts and no walks as New Orleans won 7-2.

He followed that up with a six-inning, one-hit shutout at Round Rock on May 27, in which he again struck out seven and didn’t walk a batter in getting his first Triple-A win. Then came Colorado Springs.

But Corbell said he saw a plus in that.

“I told him the big thing I took from that was the amount of composure you showed,” he said, “because you’re pitching in a ballpark that can really give up a lot even when you pitch well.”

Heaney bounced back with another strong outing against Round Rock last Saturday, striking out nine in six innings, allowing one run on five hits and a walk in an 8-2 victory.

Asked if he was ready to be called up, Heaney said he wanted it under the right conditions. The Marlins could do so without risking his status later with regard to salary arbitration.

“I feel like I am, but I don’t want to be ready to fill a spot,” he said. “I want to be ready to compete and help the team win. They’re in first place. I don’t want them to bring me up as an experiment.”

Heaney has been encouraged by his performances and progress.

“My first start, I didn’t have any clean innings; I always had a runner on,” he said. “The second time out, I felt really good. The third start, I kind of let (the hitters) dictate the game. And I felt really good the last time.”

At times, he’s been electric. His fastball averages 92-93 mph and revs up to 95. He has a good changeup off the fastball and a slider that’s a bit of a curve and quality enough to be his out pitch.

What’s most notable is his command. In his last start at home last Saturday, for instance, he threw 98 pitches, 64 for strikes.

“I just want to keep getting more consistent,” he said. “I’ve gotten better (since becoming a pro) at working both sides of the plate and up and down. My slider is tighter and my command (is) better.

“I’m just glad to have good outings against guys who have a thousand at-bats as professionals versus guys in Double-A who’ve had a hundred, or couple hundred at-bats.”

Marty Scott, the Marlins’ vice president of player development, said at the time Heaney came to the Zephyrs that they didn’t want to rush him. Zephyrs pitching coach Charlie Corbell said Heaney can pitch now in the majors when he’s good, but he has a few things to iron out and make him a better pro, such as holding runners on and being able to vary his looks and moves to the plate.

What he doesn’t need is to add a fourth pitch, such as a curve, Corbell said.

“When you have the makings of three Major League pitches, you don’t want to spread it thin,” he said. “You want to develop those and keep it that way. With his strikeouts to walks, he’s really been good.

“When a guy has three ‘plus’ pitches and can find the strike zone regularly, he’s on his way to the Major Leagues for a long time.”

Heaney’s slurvy slider is the result of him trying to add a curveball while at Oklahoma State that didn’t work, he said. But that time was the start of his ascension.

“My sophomore year I was a weekend starter, but (I) ended up a midweek starter and reliever,” he said. “But the summer between my sophomore year and junior year, I played in the Cape Cod League. I faced really good competition, wood bats, started throwing the slider a little more. I just learned what I can and can’t get away with.

“Then I had a good fall back at school, and that year, it’s crazy. I just took off.”

Hard work in the weight room also was a key.

Oklahoma State strength and conditioning coach Tracy Baldwin said Heaney’s lower body strength increased a lot. That, plus his smooth mechanics, make for a good combination.”

“He spent a lot of time on the squat rack,” Baldwin said. “He got up to 260 pounds on his squats.”

Heaney said it gave him good balance and helped his rhythm.

“It gave me stamina throughout the game and for a full season,” he said. “I came to Oklahoma State at 148 pounds and left after my junior year 180. And I’ve continued my weight training.”