Alex Brandon/AP

Adam LaRoche has made it known that he and his family like the Washington area, and he loved his teammates and wants to remain here. The feeling is mutual, as the Nationals and LaRoche started contract negotiations two weeks ago to keep the potential free agent on the team. While they didn’t wade into that, LaRoche’s parents thanked the Nationals and their fans following the crushing NLDS Game 5 loss through a Letter to the Editor at the Post printed Wednesday, another sign by those close to LaRoche that they truly enjoyed their time in Washington. (LaRoche’s dad is a former major league pitcher.)

Washington Nationals’ organization, you are a class act. Your dedication to our military is unlike any we ever have seen, and the effort you put toward making the playoffs memorable cannot be described.

Watching your fans behave with such dignity when the Nats’ dreams of extending their season came to an end Friday night demonstrated that they, too, are among the elite of this game. There was no booing, nothing thrown on the field.

They simply stood and applauded. Some even remained afterward to thank the players as they left the parking lot. Thank you, Nationals owners, employees and fans, for a night we will never forget.

–Dave and Patty LaRoche, Fort Scott, Kan.

LaRoche, 32, and the Nationals share a mutual option for the 2013 worth $10 million. To remain with the Nationals, LaRoche will have to offer a deal that extends beyond one year. After smashing 33 home runs, driving in 100 runs and posting an .853 OPS, LaRoche can command a lucrative multi-year contract on the open market if he declines the option year, especially given a free agent class bereft of potent first baseman.

LaRoche is among the most respected and well-liked players in the clubhouse, a calm and veteran leader. (He’s also a sneaky prankster.) He is a power-hitting left-handed bat in the heart of their lineup and an elite defender, holding the infield together with his uncanny ability to scoop up any throw to first base. His 10-year-old son Drake was practically the 26th man on the roster, a constant presence in the clubhouse and beloved by all. (Two moments come to mind: Drake sitting in the bullpen when his father hit a home run into the seats above him and when Bryce Harper and he celebrated the NL East title with sparking apple juice.)

“He’s a guy we really like,” General Manager Mike Rizzo said following Game 5. “He fits in great in the lineup and in the club. We’ve been talking, and we’re going to continue to talk.”

Years ago, during all those losing seasons, the Nationals were far from a destination team, some players playing to collect a paycheck. But as the Nationals re-stocked their farm system, drafted Stephen Strasburg and Bryce Harper, and their fortunes began to change, the perception of the Nationals changed, too. Signing Jayson Werth to a $126-million contract two years ago sent a message that the Nationals were willing to pay, and a lot, to attract top free agents and try to win. And now, with the expectation that they will contend beyond this 98-win season, the Nationals can use that to their advantage when dealing with potential free agents.

A result of the Nationals’ new-found winning was the building of a fan base. Players notice empty or full stands, and the fans’ demeanor. As the team won more than ever, building excitement along the way, fans flocked to Nationals Park and set a season attendance record at the five-year-old stadium. During the year, many players noted a changing fan base and support.

“You could tell early on that is was almost more of a social gathering,” LaRoche said before NLDS Game 3. “Nothing else to do, we’ll go hang out at the park. Now it’s turned into some diehard fans, people probably skipping work and skipping school to come see the Nats. Our last few regular season home games, I think were about as close to playoff atmosphere as you can get.”