Dave Hyde: One rising hope replaces a struggling one as Marlins call up Mack, demote Ramirez

MIAMI — This part never gets old. Joe Mack stood at his first major-league locker with a big smile and said, sure, he’d be nervous for his first major-league start. This is what he dreamed about ever since he held a baseball.

And Sunday, after a Double-A Game in Durham, N.C., the news came in wonderfully chaotic fashion.

“My manager brought us all in and yelled at everybody for no reason,’’ said the Marlins’ new catcher. “Then he said it was because I was going to The Show. It was definitely a shock to hear the news.”

He called his mom and dad, then his girlfriend. They came to his debut Monday night against the Phillies, along with his brother and sister. And his long-time hitting coach and his wife. And their child. And the hitting coach’s brother. And …

“A lot of people,’’ Mack said.

No, that part never gets old. It’s the other part of the story that does. Another Marlins big hope, Agustin Ramirez, was sent down to the minors because he wasn’t getting the job done.

Ramirez was the big name in the trade of Jazz Chisholm to the New York Yankees a couple of years back.

It’s good the Marlins are finding talent for low costs, such as shortstop Otto Lopez (team-leading 1.9 WAR) off waivers, reliever John King (three hits allowed in 15 innings) for $1 million and catcher Liam Hicks, a Rule 5 pickup after playing his career in the minors who entered Monday tied for second in the majors with 29 RBI.

Such low-cost stories and some strong pitching have the Marlins at a respectable 16-18 entering Monday against Philadelphia. Don’t shrug at that. This a build-with-youth roster that has a league-low $80 million payroll.

But for this latest Marlins’ rebuild to work, the investments like Ramirez have to work. The promise Ramirez showed last season with 21 home runs was tempered by his troubling defense, which hasn’t improved this year. The hitting went splat this season, too. Two home runs thus far.

“A hard one,’’ manager Clayton McCullough called the decision to demote Ramirez. “Especially the defense, that part of his game needs to continue to improve to be able to catch up here.”