At the end of a game in the summer of 2005, Mike Wallace — known in the Washington Nationals clubhouse he manages, then and now, only as “Wally” — would finish the duties that faced him every night, laundry and the like. He would return to his office deep underneath RFK Stadium. There, finally, he would climb onto an inflatable mattress, and go to bed.

“That was life,” Wallace said. “That’s what made sense then, because we didn’t know what was going to happen.”

Many of the Nationals who take the field this week at Nationals Park — a group that sits in first place despite an unsettling weekend sweep in Atlanta — understand what the franchise has been through in its most recent seasons. They lost 100 games in 2008 and again in 2009. They haven’t had a winning campaign until this one. Times have seemed tough.

But only a scant few people — some front-and-center, others behind the scenes — truly comprehend what the franchise has endured going back a decade. These Nationals were, at one point, the Montreal Expos.

By now, that fact is noted from Capitol Hill to Cooperstown almost as an afterthought. Unless you lived it.

“We knew in some ways that it was kind of like an us-against-the-world-type thing,” Wallace said. “It’s kind of like us band of brothers.”

Since moving to Washington from Montreal over the winter of 2004-05, the Nationals have had two owners, Major League Baseball and the Lerner family.

Those owners have employed two general managers, four managers, 17 shortstops and four racing presidents. They have played in one 45-year-old ballpark that had to be overhauled just to make it borderline presentable and another $611-million palace with views of the Capitol dome. In that time, Montreal slipped further into the past, and the chance to field a winner developed, however slowly, in the District.

But only a handful of people have a sense of what it was like then, and the journey to get to this point. Shortstop Ian Desmond, drafted by the Expos in 2004, and outfielder Roger Bernadina, signed by the club in 2001, are the only members of this year’s team who were in the Expos system. And they have only a scant understanding of the uncertainty around it all, because they were minor leaguers then, chasing their chance to get to the majors, no matter the city.

“They basically said, ‘We’re going to draft you,’” Desmond said. “‘You may not be an Expo, but you will be with us.’ ”

The group that has been with the franchise, from the Montreal days to now without interruption, is tiny: Wallace, the clubhouse manager, and Matt Rosenthal, who manages the visiting clubhouse; John Dever, the senior director of baseball information, who runs day-to-day media and public relations for the players, coaches and baseball operations staff; Rob McDonald, the vice president of clubhouse operations and team travel; Mike McGowan, the assistant athletic trainer; and Randy Knorr, who serves as Manager Davey Johnson’s bench coach and has managed the team’s minor league affiliates at Class A, AA and AAA. Troy Gingrich, the hitting coach at Class AAA Syracuse, has also served in the Nationals’ minor league system since the Montreal days.

Their view right now is from the top. But their existence in baseball, a game with so many shared experiences that appear unorthodox to outsiders but normal within the sport, is unique.

“It started off crazy,” McDonald said. “But then eventually, it seemed normal to us.”

Bizarre transaction

Remember, first, how the Nationals even arrived here. MLB came to own the franchise in a bizarre three-way transaction in 2002, one in which John Henry, then the owner of the Florida Marlins, bought the Boston Red Sox; Jeffrey Loria, then the primary owner of the Expos, bought the Marlins; and the league took over the Expos. That led to a situation in which Wallace and McDonald, both Marlins employees, weren’t sure for whom they worked. Wallace spent three days that spring unloading Marlins equipment at the team’s spring training compound in Viera, Fla.

“But I knew I wasn’t going to be there,” he said. “I wasn’t going to have a job.”

McDonald, too, felt uneasy staying with the Marlins under an entirely new regime. “I was the odd guy out,” he said. So he quit his job with Florida, and a week or so later was hired by Montreal. Wallace, who has worked in major league clubhouses since 1973, joined on as well. What lay ahead for everybody involved was little more than uncertainty.

In 2002, there was still talk that MLB had purchased the team in order to eliminate it, pairing it with another team from the American League — perhaps Minnesota. But the contraction talk came and went, the Expos somehow stayed in the pennant race till September, and the staff kept working. Frank Robinson, a Hall of Fame player who had been hired by Commissioner Bud Selig to be the manager, tried to keep the employees committed to the tasks before them — even as they worked in a front office of about 25 people, while most teams had four or five or six times as many.

“There was talk of contraction, but Frank would always keep us motivated and say, ‘There’s going to be somewhere for us to play. There’ll be somewhere for us to go,’ ” McDonald said. “I don’t know if he knew that or not, but it helped us stay focused.”

Dever, who spent his first five years in the major leagues with San Diego, arrived in the offseason of 2003-04. And even as the Expos played out those next two seasons — playing several of their “home” games in Puerto Rico, spending a month away from Montreal at a time — there was one issue looming over the entire operation: Where would the club end up?

“We would have exhausted ourselves if we talked about it every day;” Dever said. “I, myself, maybe wanted to talk about it more with people, but I didn’t want to bog them down.”

Knorr’s experience showed how much upheaval there was. A catcher who won the World Series with Toronto in 1993, he spent all of 2002 and 2003 with the Expos’ top minor league affiliate. He then thought he would retire. But in the winter, Robinson called. “We don’t have much catching,” he said. So Knorr came to spring training, thinking he’d serve his time there, then become a coach. But on the last day of spring training, Dave Huppert, then the franchise’s Class AAA manager, said, “I need you with me.”

“I didn’t know what was going on,” Knorr said. “So I just said, ‘Okay.’ ” He played a final season, catching 83 more games. His thanks: Because MLB owned the team, it didn’t call up any minor leaguers in September, a money-saving measure. Only then did his playing career officially end.

Eventually, the wheels started to turn. During September 2004, Wallace took a turbo-prop plane with two other Expos officials to Washington to check out RFK Stadium. On Sept. 29, MLB announced it would move the Expos to Washington. As celebrations played out in the District, club officials had to stage the final game in Montreal, where a 35-year history of big league ball ended abruptly.

“Probably one of the saddest days I’ve had in baseball,” McDonald said. “. . . You look around, and you would see grown men just crying. That kind of made it hit.”

A great unknown

There was, too, the chaos to come. Dever, a newlywed at the time, headed for his parents’ home in Rochester, N.Y., roughly halfway between Montreal and Washington. There, he stayed with his bride in his teenage bedroom, waiting for the next move. Wallace served as the equipment manager for an all-star touring team in Japan, so he had to pack all the Expos’ gear up in two weeks before heading overseas, returning to who-knows-what. None of the team officials knew what awaited in Washington — ostensibly their new home, but a great unknown, a town that had endured 33 summers without baseball. It had to get used to who the Nationals were, and what having baseball back meant.

“We’d go somewhere [in years past], and we’d say we were with the Nationals, it didn’t help,” McDonald said, laughing. “It didn’t help you get a reservation. It didn’t help with anything.”

Gradually, as the Lerners took the franchise over and put their own structure in place, other ex-Expos who helped with the transition — team president Tony Tavares, assistant general manager Tony Siegle, farm director Adam Wogan, scouting director Dana Brown and others — moved on to other jobs. And this core, with an experience like no one else in sports, is left to watch the Nationals chase a division title, and more.

“I don’t even know what to do with myself sometimes,” Dever said. “The challenges are completely different.”

McDonald said, over the course of the season, he would talk frequently with executives and staff from other teams, people who would suddenly say things like, “You guys are going to make the postseason. You guys look great.”

“It doesn’t feel that way to me,” McDonald said. “Maybe because we’ve been in this situation so long, and you still look at other clubs as, ‘These guys are better than us. We hope we can beat these guys.’ It’s just now starting to sink in that we’re good.”

As of now, no team has a better record than the Nationals. But stability takes other forms as well. Wallace no longer sleeps on an inflatable mattress at the ballpark; he lives year-round in Sterling. McDonald owns a condo in Northwest, and he no longer spends his offseasons in Arizona or Montreal. “I’m a Washingtonian now,” he said. Dever’s oldest daughter was born here during the 2005 season. He and his wife bought a place in Alexandria, welcomed another daughter in 2009 and have a third child on the way in November — a family that has known nowhere else as home. On the field, Desmond is the Nationals’ starting shortstop, Bernadina an important reserve outfielder, Knorr a potential managerial candidate some day.

And whatever happens the rest of the season and beyond, only they can look back over the past decade and truly understand what it took to get here, to the middle of September, with a pennant race in Washington that has roots elsewhere.

“We appreciate how much each other enjoys the game, is true to the game, because most people wouldn’t have put up with a lot of that,” Dever said. “They would’ve sought refuge somewhere else. And we have used each other as sounding boards — psychologists, probably — and helped ourselves collectively get through it. If I left here tomorrow, these people would be important in my life for a long time.”