As a young boy in his native Dominican Republic, Rafael Soriano knew he would either end up in the military or as a baseball player. He loved both, but his mother was reluctant to allow him to join the military at 15 years old when a friend tried recruiting him. He pursued baseball, made it to the United States, became an all-star closer and earned tens of millions.

In 2003, his second season with the Seattle Mariners, Soriano was connected through a friend with a colonel in a branch of the Dominican military. Soriano told the officer about his admiration for the military. And soon, Soriano was brought into the Dominican Air Force, an honorary placement, a distinction also bestowed upon other major leaguers from the Dominican. But Soriano took it a step further. He began coaching the Air Force’s baseball team, serving as an unofficial pitching coach during the offseason.

Soriano, 33, is back at home in the Dominican now with his family and soon he will begin stopping by the nearby military base to coach this year’s baseball team. He donates equipment and uniforms. He has risen all the way to first lieutenant, with a promotion to captain coming perhaps this winter, he said.

“I’m looking forward to getting back” to coaching the players, Soriano said in Spanish during the final week of the regular season. “I love being around them. I like it. They’re disciplined and they respect me. And I’ve been doing it for a while. They’re comfortable with me and they listen to me.”

In the Dominican, where baseball is king, even the soldiers take part. The three branches of the military — the navy, air force and army — along with the national police, play each other in tournaments. Soriano said the baseball season begins early in the year, around February, so he is only home in the offseason while they practice. He stops by the military base to work with the players on occasion.

In Washington, Soriano is seen by many as the quiet, quirky teammate. He occasionally teases teammates, laughs loudly, has invited the team over to his Atlanta house for dinner and even brought homemade food to share during spring training. But he normally keeps to himself. He generally stays in his corner of the clubhouse, sometimes talking with fellow Latin players, and is often on the phone with his family and relatives back in the Dominican. He has a strange routine on the mound before he pitches, and violently untucks his shirt after a save. He may be different that most Nationals players, but above all else, he values respect and discipline — core values of the military.

“It’s something honorable and has discipline,” Soriano said. “Like baseball, the military is something that requires discipline. Without it, you can’t do it.”

Soriano lives by that code. If practice begins at 8 a.m., it starts literally at that moment. When he comes by practice, he wakes up at 7 a.m., gets ready and makes the short trip to the base, getting there in time for the morning raising of the Dominican flag. If players show up after he does, they are punished with a day of detention.

“I’m major leaguer, the officer, and I’m the one setting the example of getting here early,” Soriano said.

Few — maybe less than a handful — of Soriano’s Nationals teammates even knew he was in the Dominican military and was a first lieutenant. Craig Stammen, whose locker is across from Soriano’s in one end of the Nationals clubhouse, wandered over one day late in the season as Soriano was talking about it. Stammen laughed and looked puzzled when he first heard of Soriano’s military background. “Really?” he said.

Soon enough, the Nationals’ closer, the man with the $28-million contract, may be known within the clubhouse as Capitán Soriano.