Peter Moylan is back for a third stint with the Braves at age 39, and the gregarious Aussie reliever’s locker stall is directly across the mostly prospects-filled half of the Braves’ clubhouse from a kid barely half his age whom Moylan was teammates with in the Australian Baseball League two winters ago.

You may have heard of the youngster: Ronald Acuna.

“Ronnie and I have a history,” said Moylan, who first saw Acuna at Braves extended spring training in March 2015, when Moylan was a player-coach in the minor league system while rehabbing from a second Tommy John surgery.

Acuna was a skinny 17-year-old outfielder that spring at Braves minor league camp.

By the time Moylan saw him some 20 months later in the pitcher’s homeland winter league, Acuna was well on his way to becoming what he is today, the consenus No. 1 prospect in baseball.

“He was in extended (spring training) when I was a player-coach,” Moylan said. “Then he comes over to Australia and he goes bananas. ... He was (an expletive) stud. I was pitching on the (Melbourne Aces). I was a coach and also pitching.”

The Braves sent Acuna to Australia to get at-bats after a thumb injury caused him to miss more than half of the 2016 season at low Single-A Rome. The Aussie league was the best they could find to place such an inexperienced young player on such short notice that winter.

Feb 17, 2018 Lake Buena Vista: Braves outfielder Ronald Acuna, rated the consensus No. 1 prospect in baseball this winter by several experts, works the outfield during spring training on Saturday, Feb 17, 2018, at the ESPN Wide World of Sports Complex in Lake Buena Vista.     Curtis Compton/ccompton@ajc.com

Credit: ccompton@ajc.com

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Credit: ccompton@ajc.com

Halfway around the world, the Venezuelan outfielder excelled against mostly older competition in the Aussie league, which is when a lot of folks inside and outside the Braves organization begin to recognize just how good a prospect he might be.

In 20 games with the Melbourne Aces, Acuna hit a blistering .375 with eight extra-base hits (two homers), 13 stole bases, a .446 OBP and 1.001 OPS, and made the midseason All-Star team. He left midway through the season for what was said to be visa issues in Venezuela.

“He was the best player in the league,” Moylan said. “They talk about a five-tool player – and he’s probably a six-tool player because he’s got his head screwed on straight, too. ... He was an absolute stud. A lot of the times when prospects come over to Australia they’ll struggle a little bit. But he just grabbed a hold of it from the first game.

“In the first series, he stole home. It was the second or third game of the series and he stole home, and it was the winning run. It was awesome.”

Acuna, who turned 20 on Dec. 18, is one of the players in the Braves clubhouse whom Moylan was referring to Tuesday when the reliever said there were a lot of guys in camp young enough to be his children.

“It’s an exciting time to be around the organization,” he said. “I think I can pass off some (advice) to them, not so much pitching, but the other stuff – the mentality and mindset. We’ll see.”