A comparison of the Washington Nationals' projected lineups in 2017 and 2019. (Eddie Alvarez/The Washington Post)

Three glass panels hang on the wall just outside the Washington Nationals’ spring training clubhouse, each of them a couple feet wide and a few feet tall. Names cover them from top to bottom, listing every player to win an award in a Nationals uniform, from MVP to player of the week.

Read in their entirety, those panels narrate the maturation of an adolescent franchise that once struggled to attract or develop star-caliber players but evolved into an organization that could afford to let talent go.

Some of the names, such as Ian Desmond and Jordan Zimmermann, belong to players who came and went. Some, like Ryan Zimmerman, belong to stars who faded into the backdrop as younger talent emerged. So far, none of those comings and goings have disrupted the Nationals’ trajectory, which seems steady after three 95-or-more-win seasons in five years.

But as the Nationals begin the 2017 season, defending National League East division champions, still hunting their first playoff series win, change looms. Free agency threatens to dislodge several pillars of their clubhouse; Jayson Werth after this season, Bryce Harper, Daniel Murphy and others after next. Mike Rizzo’s contract expires after next season, too, threatening the rare continuity he built here.

These Nationals, these familiar ones, the first generation of this organization to be successful, might not have much time left. Some of them buy the idea that their window is closing. Others, who perhaps heard about a closing window once before then won a division title the year after it was to have shut, are more skeptical. Regardless, this season and next might bring these Nationals their last chances to turn regular season success into postseason magic, because change is coming, whether a title does or not.

Nationals outfielder Bryce Harper is under contract for two more seasons. (Toni L. Sandys/The Washington Post)
THE SUPERSTAR

Bryce Harper’s name is on those glass panels 16 times, for everything from his 2015 MVP award to a couple player of the month honors. All those accolades might earn him a record-breaking contract two years from now when he becomes a free agent for the first time.

But all those accolades also earn Harper the joys of endless scrutiny, of unending analysis of his and the Nationals’ every word about his future. Will the Nationals bid to keep him? Does he want them to, or is the draw of a supersized market too strong? Can the Nationals even afford him?

Harper is not saying much at all. He is quieter now than before, more reticent in most interviews, more reluctant to give them than he used to be. When people ask, he says the right things about his future, namely that he is not worried about that right now because he still has two years to play in D.C.

If the Nationals have a two-year window, Harper does, too. The 24-year-old has two seasons to prove he is more MVP than midlevel all-star, to prove he is more the 2015 Harper than the 2016 version. Hundreds of millions of dollars and baseball contract history — whatever that is worth — depend on it.

But whether Harper is more a .243-hitting, 86-RBI all-star or a transcendent legend-in-the-making, he is the engine that drove the Nationals’ emergence. If Zimmerman is the player who put the Nationals on the map, Harper is the man who spread the curly W across it. Harper understands legacies, the rarity of playing a whole career with one team. And he understands that this team is building its tradition around him, before his eyes.

“I think about the fact that when people grew up in Maryland, D.C., Virginia, with Cal Ripken and all those great teams, they were going to Camden Yards, watching a great organization,” Harper said.

“But the young fans we do have now, they’re all growing up. You have 10-year-olds that are 15 now, they’ve always been Nationals fans. It’s getting to that point. The more they get older and their kids, it’s just going to grow.”

Nationals general manager Mike Rizzo, left, and Mark Lerner, son of 91-year-old Ted Lerner, in 2012. The Lerners are the franchise’s owners. (Alex Brandon/Associated Press)

In trading for Adam Eaton and in holding tight to Victor Robles, the Nationals started building for a post-Harper world. In speedy Eaton and Robles, they can have left and center covered by the time Harper’s contract expires, leaving them to re-sign him or find a corner outfield type to replace him. Rizzo and the Nationals are planning in case of Harper’s departure, which is not the same thing as counting on it.

Harper said he trusts in Rizzo’s plan, in the process and consistency Rizzo established in the minor leagues and the draft, and thinks that continuity will keep the Nationals within an acquisition or two of sustained success.

“I mean, there’s so many guys on this club that can help us in the long haul as well,” Harper said after rattling off nearly every young player on the roster. “Everybody talks about now. This year, next year — the window. But our window’s long.”

THE VETERAN

“I don’t really look much past myself. I’m not really concerned about what happens after I leave,” Jayson Werth said with a smile, leaning against the wall across from those glass panels, where his name appears just three times, under National League player of the week and month.

Those panels do not tell Werth’s story well. He has not made an all-star team as a National, never won a Gold Glove or Silver Slugger. But for six years he has presided over the Nationals’ clubhouse, the constant leader, more a pitch pipe for the players in that clubhouse than a preacher with a pulpit two lockers wide. Werth will be a free agent after this season, free to sign wherever he pleases, and end a seven-year tenure with the Nationals marked so far by success — but no titles.

“My window is now,” Werth said. “ . . . I’m not discounting the fact that I could be back next year. That’s not out of the realm of possibility. But I don’t know how likely it is. In that regard, the window is definitely now.”

When Harper or Trea Turner or other young players talk about Werth’s clubhouse impact, they talk about his clout, his experience with winning in Philadelphia, where he was a World Series hero in 2008. Being on a team that has won a title amounts to a graduate degree in baseball, an extra level of education, an added dose of credibility.

Werth signed with the then-hapless Nationals hoping to lead them to a title, to prove they could win. So far, they haven’t. Whether they win this year, Werth said, will determine whether he views his Nationals tenure as a success.

But independent of results, Werth does seem proud of the clubhouse culture that emerged under his watch — a laid-back, do-your-job type environment built somewhat in his image. Continuity helped solidify that culture, Werth said. Then that culture helped establish continuity.

“For the most part, we have the same nucleus of people that we’ve had. We lost [Desmond], who was a big part, but then we got Murph. We lost [Danny Espinosa] this year, but Trea’s stepped up. He’s become one of the guys,” Werth said. “Look at Trea. When he got here in September two years ago, he was a totally different person. This team has helped shape him.”

Turner will shape the Nationals’ future. Werth shaped their present, much like Ryan Howard, Chase Utley, Jimmy Rollins and other core members did during his run with the Phillies in the late 2000s. That team, seemingly built to last like these Nationals have been for the past five years, slid into a rebuild soon after a few key pieces left.

“Age and injuries,” Werth explained. “Father Time is undefeated.”

THE ACE

Max Scherzer’s name is the second one to appear on those panels, just below Harper’s, the only name listed under National League Cy Young Award. For someone two years into his Nationals tenure, he occupies plenty of space on those panels, under pitcher of the month and pitcher of the week and National League all-star.

Scherzer signed his seven-year deal with the Nationals in part because he wanted to be somewhere he could win long term. After what he called a five-year window of winning in Detroit, he is now in his third year of title contention with the Nationals.

“Of course there is [a window]. That’s sports now,” Scherzer said. “ . . . We’re in a win-now situation, and that’s where you want to be.”

Scherzer has a hypothesis about baseball sustainability: If a team gets production from young players, the ones with zero to six years of service time whose salaries are limited by arbitration, that team will win.

“Right now, we have guys that fit that mold, that will be a part of this organization for several years now,” Scherzer said. “We can keep replenishing talent around here because of the job the front office has done to acquire young talent.”

Turner, Anthony Rendon, Koda Glover and Joe Ross are players under team control long past the 2018 season. Though Scherzer does not fall in that zero-to-six mold, he, Stephen Strasburg and Tanner Roark are all under contract past the 2018 season, too. The team will turn over around them, but the nucleus of the starting rotation tied for the best ERA in baseball since 2014 is not going anywhere.

“You look at 2017, we’re going to be able to compete for a World Series. I don’t know how far we go, but we’re definitely able to win this thing,” Scherzer said.

“ . . . but if you do a little counting around in the clubhouse, we should be able to be competitive for a few more years as well. You don’t see any reason for a drop-off.”

THE GM

Rizzo negotiated his contract with the Lerner family when the owners signed him to a three-year extension after the 2013 season, so he does not bring that contract up. He said he has not talked to the family about his future since the Lerners picked up the 2017-18 option on his deal midway through last season.

“This is the organization I built from scratch. I feel it’s my home. I would feel very comfortable being here long term,” Rizzo said. “But we have a contract. I’ve never brought it up. If one day they approach me, we’ll discuss it, and I’d be happy to stay.”

After building the Nationals into an annual contender and creating uncommon continuity in their minor league infrastructure, Rizzo will likely require a pay bump and perhaps be a coveted commodity two years from now.

And while Rizzo always says the Lerners give him everything he needs to build a winning organization, those who work closely with him express frustration about the sometimes-winding ways in which the franchise operates. Some wonder if the appeal of fewer hoops to jump through might draw him elsewhere. Rizzo has never said as much.

“We’ve been highly scrutinized on how we do our business, but we do our business pretty well. I’ve seen ‘dysfunction’ and stuff like that. We are not dysfunctional,” Rizzo said. “When you have the track record we have, the communication I have with the owners — Ted and I specifically, me and them — I think it works for us.”

The Lerner family has its own kind of urgency, one that has hovered around the Nationals for a few years now. Ted Lerner, the patriarch, is 91 years old, and the family wants him to see his team win a title. He has overseen the building of a new stadium and a new spring training facility. The Nationals will host the All-Star Game in the summer of 2018, when Nationals Park turns 10 years old. Lerner has overseen the Nationals’ emergence to respectability. Things will change without him. Things might change anyway.

His family oversaw every detail of the construction of the Nationals’ side of the Ballpark of the Palm Beaches, and in keeping with those duties, will probably have to order a new glass panel soon. The three that hang there now are filled, with no room left for one more player of the week award, let alone an MVP or something like that.

The next panel will carry the conclusion of this chapter of the Nationals’ story. The names etched there will probably reveal whether this group — intact for now but perhaps not for long — won it all before the window slid shut, or if they actually had a window to worry about after all.