The club is about to find out.
After losing, 5-0, to the Dodgers on Sunday afternoon, the Marlins announced catcher Brett Hayes was being optioned to Triple-A New Orleans, and Brantly was being promoted to the big leagues.
A left-handed hitter, Brantly had been at New Orleans since being obtained from Detroit as part of the Anibal Sanchez/Omar Infante deal.
"When you give up the kind of players that we gave up, that's the kind of player we are looking for -- an everyday catcher," Marlins president of baseball operations Larry Beinfest said. "We think he can do that. But he hasn't played in the big leagues yet."
The book on Brantly is he's a quality hitter who still needs improvement behind the plate. In 14 games with the Zephyrs, he batted .365 (19-for-52) with two home runs, four doubles and 11 RBIs.
"We heard he had good [offensive] upside," Beinfest said. "Again, it's a small sample size, but he's hit the ball very well. They love him down there, the guys throwing to him. Still working on some defensive stuff, but he can work on it up here. We'll take a look."
The intent is for Brantly to play. But how much?
John Buck, signed through 2013, has been the regular. But the veteran has struggled with a .186 batting average, with eight homers and 30 RBIs.
In August, however, he is 10-for-30 with seven doubles.
Perhaps, Brantly and Buck will platoon.
"We're going to try to figure out playing time," manager Ozzie Guillen said. "This guy is coming to the big leagues, he needs to play. I don't know how many days a week we're going to play him, but we'll figure it out to give him enough playing time."
Hayes has been the backup the past two seasons. He started in Sunday's loss, and was hitless in three at-bats with two strikeouts.
For the season, Hayes hit .202 in 39 games.
The Marlins are searching for offense. On Sunday, they were limited to two hits in their 11th shutout of the season.
Brantly will get a chance to see if he can produce.
"I don't know that you'd want to bring a young guy up and sit [him], either," Beinfest said. "We'll try to get him in advantageous situations for him. But he also needs to play."