Spring training storylines: Is this last shot at winning it all?

The final countdown to spring training has arrived, so we're spending the final days of the offseason counting down the Nationals' top storylines of the spring. We conclude today with the underlying question not only of the spring but of the season: Is the window of opportunity for this franchise about to close at the end of 2018?

We can talk about position battles, lineup choices, bullpen configurations and injury concerns all we want, but let's not ignore the elephant in the room. The singular storyline of the 2018 season for the Nationals isn't so much about what happens between February and September, but what happens in October, and whether this team is down to its final shot at winning something big in the postseason.

Such is the price of regular season success over the last six years; the Nats' .571 winning percentage since 2012 is bested in the majors only by the Dodgers' .575 mark. And such is the price of postseason failure; 16 other major league franchises have won at least one playoff series or wild card game since 2012, while the Nats have gone 0-4 in the National League Division Series.

Every spring during this stretch, we've wondered whether this will be the year. But this spring, we must add some awfully important context to that question: Given the departures that already have occurred and several more likely to come next winter, does this have to be the year for the Nationals, lest they completely squander this window of success?

Club executives, staff and players alike all insist they do not view the situation in those terms. This isn't an all-or-nothing season, and this team still will be positioned to contend in 2019 and beyond.

"We've got a strategy in place," general manager Mike Rizzo said. "We've got a blueprint to be good for a long period of time. And that continues."

In Rizzo's defense, there remain enough talented pieces under club control beyond this season to form a very good roster. Who wouldn't want to start with a core group of Max Scherzer, Stephen Strasburg, Anthony Rendon, Trea Turner, Adam Eaton, Michael A. Taylor, Ryan Zimmerman, Sean Doolittle and (probably) Victor Robles?

At the same time, it would be foolish to gloss over the harsh reality of the situation. Ian Desmond, Wilson Ramos, Jayson Werth, Jordan Zimmermann and Denard Span are long gone, and Bryce Harper, Daniel Murphy, Gio Gonzalez and Ryan Madson might well join them and wear different caps in 2019. Oh, and possibly even Rizzo himself, with his contract expiring in October.

That's a lot of core muscle to lose in the span of three years.

Then consider that a year from now, Scherzer will be 34, with 11 seasons and 2,000 innings of big league time on his odometer. Zimmerman also will be 34, with 14 full seasons and 7,000 plate appearances to his name. Strasburg will be 30. Tanner Roark will be 32.

They've still got young players to build around - Rendon, Turner, Taylor, Robles, maybe Joe Ross, Erick Fedde and Pedro Severino - but the Nationals are going to have to find more ways to get younger, and do so without sacrificing their chances of winning.

On top of all that, consider the rest of the NL East, which aside from the Braves in 2012-13 and the Mets in 2015-16 has been abysmal. Amazingly, out of the 30 total team seasons played in the division since 2012, only 10 have produced winning records, and six of those belong to the Nationals. (The Braves and Mets each have two winning records, the Phillies and Marlins have zero.)

That dynamic may remain the same this year, with the Mets needing a whole lot of things to go right to get back into contention and the Braves and Phillies needing the rewards of their long-term rebuilding plans to pay off a year earlier than expected. But this should be a very different division in 2019, with Atlanta and Philadelphia well-positioned to finally make their move back up the ladder.

So that's the context under which the 2018 season will be played in Washington. There would have been pressure on this team regardless, but the specter of the major changes ahead will add an extra layer of urgency to everything that takes place over the next eight months.

No, the window isn't closing entirely for the Nationals. But make no mistake: This is their last best shot, and they know it.