MIAMI -- Miami Marlins catcher JT Realmuto had to make his case -- without much argument -- for his final at-bat of a 14-6 rout of the Boston Red Sox on Wednesday.

Realmuto, a double shy of becoming the first Marlins player to complete the cycle, was in the midst of a historic day in his very young career. Though he struck out swinging on Tommy Layne's 89 mph fastball -- a pitch he usually wouldn't go out of the zone for -- in the eighth inning, it took nothing away from his performance.

"That's all I was thinking about," said Realmuto, who fell a triple short of the feat earlier in the season. "I went up with the intention I was going to swing no matter what. I think he might have known that because he wasn't going to throw me a strike that last pitch. ... I was laughing because that 3-2 pitch I told myself I'm swinging no matter what."

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Nothing to be upset over for Realmuto, who finished the game 3 for 5 with a career-high six RBI. He tied Charles Johnson (June 23, 1995) for the Marlins record for RBI in a game by a catcher. The only backstop with more RBI in a contest against the Red Sox was Yogi Berra in 1957 (eight).

The 24-year-old rookie drove in Cole Gillespie with an RBI triple in the second. In a 10-run sixth, Realmuto collected two hits. His RBI single scored Justin Bour, while his grand slam -- the first of his major-league career -- punctuated the historic frame.

Miami also compiled a 10-run inning on July 9, 2009, in Arizona. Realmuto's five RBI in the inning set a new club record. His triple tied him with Dee Gordon for the team lead with six. He also matched the single-season record by a Marlins catcher, also done in 1993 by Benito Santiago. The last catcher with seven or more? Darrell Porter (eight in 1979 with the Royals).

"I've been feeling good at the plate lately, just got to take advantage of these times because when you feel hot like this it doesn't stay for too long," said Realmuto, who went 5 for 10 on the brief two-game homestand. "Just got to keep taking advantage and keep scoring runs and winning games."

Like a few of his teammates, Realmuto's presence in the lineup has come due to underperformance. Miami designated Opening Day starter Jarrod Saltalamacchia for assignment before May. Realmuto, anointed the backstop of the future, suddenly got thrown into the starting role.

It hasn't come without growing pains.

According to manager Dan Jennings, hitting coach Frank Menechino keeps track of line-drive outs. With some hard luck, Realmuto is batting .255 rather than in the .280-.290 range. After putting together a nine-game hit streak on July 29, he posted a .115 clip (3 for 26) entering this Red Sox series.

"It gets pretty frustrating, especially once they told me the number it was," Realmuto said. "I kept doing it and it gets in your head a little bit. All you can do is go up there and do your job, which is hit the ball hard and square it up. And sometimes you get unlucky and things will turn around eventually."

Wednesday's starter Adam Conley, a 25-year-old rookie southpaw who made his second big-league start, is in awe of his battery mate. A high school shortstop, Realmuto didn't take on catching duties until beginning his pro career after the Marlins selected him in the third round in 2010.

Since June 3 over a span of 47 games, Realmuto is hitting .294 with 10 doubles, three triples, five homers and 25 RBI. He paces all catchers with six triples and ranks second with four stolen bases thanks to his speed.

Among rookie catchers in club history, Realmuto has already surpassed Johnson with 80 hits. His 29 extra base hits (16 doubles, six triples and seven homers) showcase his penchant for solid contact.

"I came up playing with him and stuff," said Conley, who got a no decision after 4 2/3 innings of work. "He's been up here for a little while, but you just love seeing a friend of yours, a guy you've played with and grown up with a little bit in pro ball to have a day like that is awesome.

"I think his consistency of showing up to the field every day wanting to be great, constantly wanting to learn. ... To be 24 years old or however young he is and make it to the big leagues and be catching at that level he is right now just a few years after being a shortstop after high school. You can't say enough about it. There's very few people in the world -- let alone baseball-- that could make the adjustments he's made and improved the way he's improved both behind the plate defensively. And obviously offensively you see what he did tonight."

At a position such as catcher that values the defensive aspect so much that it can disregard offensive ineptitude, Realmuto's skill set at the plate is a luxury. So much so he noted that infield coach Perry Hill wants to work him at third base during spring training.

On scheduled offdays behind the dish, his bat can remain in the lineup either at third or left field. San Francisco has done the same with All-Star Buster Posey at first base. Minnesota with All-Star Joe Mauer.

"This guy has a chance to be an All-Star player for a long time," Jennings said. "He's a tremendous athlete, No. 1, and he has such offensive value and you just watch him really every month. We talk about him taking leadership of this team and running the pitching staff, and he's stepped up in a huge way, and it's good to see him do that."

You can follow Christina De Nicola on Twitter @CDeNicola13 or email her at cdenicola13@gmail.com.