Later, Gronauer became an Alligator, overwhelming the local competition but never realizing his potential. He knew he was good for an amateur player, and he knew he was good when he joined the German national team as a teenager. He just didn't know what any of that meant.
"It would be similar to being a cricket player from the United States," said fellow catcher Mike Nickeas. "It would be difficult to kind of benchmark yourself compared to other athletes."
It was not until a two-week international tournament in Barcelona that Gronauer caught the eye of Major League scouts and realized he was a good baseball player, period. Contract offers began coming in from big league teams, including a two-year deal from the Mets that lured him to rookie ball in Port St. Lucie.
Then, at some point shortly after arriving, Gronauer looked around and realized, "Oh God, it's different here."
2010 Spring Training - null
Sights & Sounds
Spring Training Info
"It's a lot harder," he said, reflecting back on his early days in the States. "It's tougher. I didn't know if I could do this. But then, at the same time, I thought, 'Well, I'm having fun here doing my job. I would not like to be in an office in Germany right now doing paperwork.'"
His office instead is an oversized catcher's locker at Digital Domain Park, five stalls down from Nickeas (who played for Great Britain in the Barcelona tournament) and four down from starting backstop Josh Thole. Unlike those two, Gronauer will not break camp with the Mets; he'll probably be among the first players cut for the second consecutive spring. But there's little shame in that. In fewer than three years, the 24-year-old has transformed himself from an international question mark to a legitimate catching prospect in big league camp.
"It's baseball heaven. It's unbelievable," Gronauer said. "I have no idea how to put it in words, as happy as I am."
It wasn't always that way. In his first season stateside, Gronauer broke his thumb and missed four months, appearing in only 16 games. He was lonely in Florida, not accustomed to a culture saturated by smartphones and hamburgers.
"You miss your family," Gronauer said. "You miss the food and everything."
Struggling again the following season in Class A ball, Gronauer returned to the South Atlantic League last spring and improved his numbers across the board. That earned him a promotion to Class A Advanced St. Lucie, where Gronauer batted .324 with two home runs in 139 at-bats.
Now, the trepidation is gone, the culture shock has faded and a quick glance at Gronauer offers little hint at the man's German upbringing. His accent is noticeable only when he is searching for a particular word -- one of Gronauer's favorite foods, for example, is a type of stew he cannot translate into English.
Catching Venezuelan teammate Francisco Rodriguez's bullpen session on Wednesday, Gronauer sounded like any other backstop in camp, yelling out encouragement each time Rodriguez popped his glove with a particularly well-placed fastball. His demeanor reveals nothing of his heritage. Gronauer may miss cabbage stew, but he never shows it.
"That was the surprising thing," Nickeas said. "I think he's assimilated himself very well. He handles himself properly, like he's been an American."
If Gronauer eventually advances to the big leagues, he will become one of about three-dozen Major Leaguers born in Germany or West Germany, a list almost completely devoid of players who were also raised in Europe. Most, like pitcher Edwin Jackson of the White Sox, were born on military bases and raised in the United States. Gronauer could become a notable exception.
His ultimate hope is that success here will breed interest back home, where even Gronauer's family does not entirely understand the nuances of the game. Among European nations, Germany lags well behind Italy and the Netherlands -- which draws its talent largely from Caribbean islands Aruba and Curacao -- in terms of baseball pedigree.
Gronauer aims to change that.
"I want to be an ambassador for baseball, especially in Germany," Gronauer said. "It's a very interesting sport. I think German people could be interested in it."