“Circumstances, we just have to see what they’re going to do with Zim [Ryan Zimmerman], said Adam LaRoche, who will likely cede first base to Zimmerman as age and injuries catch up to the former third baseman. “I think that’s probably what it will come down to. He’s our best hitter. He needs to be in the lineup.” (John McDonnell/The Washington Post)

For so many reasons, Adam LaRoche wants to stay. He adores his Washington Nationals teammates. He believes the team that was — in his words — “terrible” when he arrived will win into the foreseeable future. He sees people in Nationals caps around his home in McLean, and when he first came here he never saw Curly W’s even in the District, and it means something to him that he will tell his grandchildren: He was there when Washington flipped and became a baseball town.

For so many reasons, LaRoche knows he probably will leave. His contract runs out aside from a mutual option, a clause almost never activated by both parties. He realizes Ryan Zimmerman’s future is at first base, the position LaRoche filled for the past four seasons. He knows a baseball life means an itinerant life and that things happen and people and teams move on.

And so this October was likely LaRoche’s last ride with the Nationals — the last time the beloved teammate, dependable first baseman, genial outdoorsman and charitable man will wear a Nationals uniform. If the decision was his to make, in a vacuum, LaRoche would finish his career in Washington. He knows it is not, and he is okay with that.

“I would assume if there was a spot for me to play, my guess would be they would want me to come back,” LaRoche said. “Without a doubt, this is where I would like to play next year. If I could pick between every team in the league, I would pick here. I’m not just saying that. I’ve got too many close friends here. I really, really enjoy playing here. If it was up to me, I’d be back.

“Circumstances, we just have to see what they’re going to do with Zim. I think that’s probably what it will come down to. He’s our best hitter. He needs to be in the lineup. If he needs to move over to first to make that possible, then that kind of weeds me out, and I move on. Which is fine. It’s not the first time I moved to a different team.”

Washington Nationals players expressed a mixture of pride and regret after their loss to the Giants on Tuesday, with some already looking forward to spring training. (Whitney Leaming/The Washington Post)

LaRoche’s expected departure could be easier on him than on the Nationals’ clubhouse. In the back corner, next to Jayson Werth and Zimmerman, LaRoche helped create and ingrain a new culture. He also knew when to have fun. He brought a giant potato gun to spring training. He passed out T-shirts and hats emblazoned with logos from his E3 Ranch and Buck Commander hunting company.

“He’s one of those guys you call a good teammate,” Werth said. “At the end of my career, if that’s all they say about me, I think I did my job.”

LaRoche’s son, Drake, became part of the clubhouse atmosphere, too. (“Shoot, they may re-sign him and not me,” LaRoche said. “We may be on separate teams next year.”) When the Nationals summoned Tyler Moore from the minors early this season, LaRoche invited Moore to stay with his family — wife Jen, kids Drake and Montana — in McLean. Moore said he wouldn’t mind a hotel. LaRoche insisted.

“He’s been a great friend,” Moore said. “You appreciate that, and it’s something you can have for the rest of your life, just the few years we’ve been together. That’s just kind of his character. That’s what makes him so good. He cares about people, man.”

LaRoche played through injury, anchored the middle of the Nationals’ lineup and gloved every throw in his vicinity at first base. His defense solidified an infield that, with Adam Dunn at first base, frequently had betrayed its pitching staff.

“He’s one of the best first basemen I’ve ever seen play,” Zimmerman said. “I’ve learned a lot watching him over there, whether it’s watching him from the bench or being at third. At some point when I play over there, watching him for these five years, whatever it’s been, will definitely have a positive effect on what kind of player I am.”

Aside from his slugging and defense, LaRoche’s presence imbued the young infield with confidence. Before LaRoche took over in 2011, Ian Desmond made 34 errors throwing to Adam Dunn. In the four years since, Desmond has averaged 20.5 errors. Desmond deserves credit for his own improvement, but LaRoche’s presence made an impact.

“Above anything else, when he came here, for the first time for all these guys, they had a guy at first base that could pretty much catch anything they threw over there,” Werth said. “It gave the infielders confidence. That’s something they hadn’t had up until that point. In that regard, it really catapulted some guys’ careers in a sense.”

Given the construction of the Nationals’ roster, LaRoche cannot stay much longer. Zimmerman’s battered right shoulder forced him to switch to left field this season when Bryce Harper was on the disabled list. But with Harper healthy, the Nationals’ outfield is set with Harper, Werth and Denard Span, with prospects Michael A. Taylor and Steven Souza Jr. in the wings.

If Zimmerman stayed at third, LaRoche likely would come back, perhaps on a one-year, mutual option worth $15 million. (The Nationals would incur a $13 million expense because it costs them $2 million to buy him out if LaRoche accepts his half.) But Zimmerman knows playing the position he loved on an everyday basis is behind him.

“That’s part of the game,” Zimmerman said. “As people play the sport, as you evolve, things happen. Do I wish that some of the injuries I had hadn’t happened and I could continue to play third base, like I enjoy doing? Of course I do. But things happen. They’re not easy decisions. It’s not easy for me to say I have the possibility of moving from third base. It’s reality. It’s more important to look at what he’s done while he’s been here and how much he’s meant. He’s been a great guy. He never complains.”

When LaRoche returned to the Nationals two years ago, Drake and Montana asked him to consider staying home. “They’ve been wanting me to retire for two years,” LaRoche said, laughing. LaRoche, 34, is not yet ready to call it a career. In some ways, his 11th season was his best. He grew more selective at the plate, setting career bests for a full season with 82 walks and 108 strikeouts. He feels like he is still learning about himself and about the game.

“I do not want to ride this game out and try and suck every dollar I can out of the game,” LaRoche said. “That’s not me. I love the game but not to the point where I’m going to just leave with nothing left in the tank. On the other hand, I got this fear of leaving too early and looking back two or three years down the road and really regretting not playing when I felt good physically and mentally to do it. I doubt it.

“If this physically would have been a tough year — back or whatever — I think I would have definitely considered [retirement]. I still feel really good. I still feel like I can be productive. I almost feel like I’m in some aspects better now and still learning. I almost feel like I’ve got better years than I’ve ever had in front of me.”

LaRoche will not overstay his time in baseball, in part, because of everything he does away from it. “If anything, the baseball season is when I actually get to relax and let other people worry about that stuff,” LaRoche said. “When I get home, that’s kind of when the grind starts of people leaning on me.”

There is LaRoche’s Buck Commander hunting company, which produces videos, entices sponsors and is adding new products weekly, LaRoche said. LaRoche and his brothers own two restaurants in Steamboat Springs, Colo., a Mexican cantina and the E3 Chophouse, a new steakhouse that he stocks with all-natural beef from his E3 Ranch in Fort Scott, Kan.

LaRoche also is funding a high school baseball stadium in Fort Scott, which he hopes will grow revenue for the town and boost the local team. He financially supports three mission groups in Ethiopia, India and Thailand, providing aid and Bibles translated into the native language. He took part in a USO Tour last winter, and he works closely with the Wounded Warrior Project, donating money and personally meeting veterans. He is one of three finalists for the MLBPA’s Marvin Miller Man of the Year Award.

“This game has afforded us to have a ranch and do all this awesome stuff,” LaRoche said. “The old saying it’s better to give than to receive really is true. We’re blessed to be able to help out some of these organizations.”

When LaRoche departs, the Nationals will lose a slick first baseman and a veteran slugger still figuring out the game. And they also will lose much more.