The Post Sports Live crew debates whether Bryce Harper's comments about manager Matt Williams's lineup are potentially damaging for a team that just got back to full strength on Monday. (Post Sports Live/The Washington Post)

In winter, baseball franchises build wonderful-looking teams that thrill their fans with possibility, but once the annual reality of injury and age arrive, those teams never take the field in the summer intact.

Fans hate to watch their teams fail, though they know that’s part of the risk of chasing greatness. What’s far more frustrating, what feels deeply unfair, is for a 25-man roster, under construction for years, never to get an extended chance to play together.

There is a worse answer in sports than, “You’re not good enough.”

It is, “You’re never going to be able to show whether you’re good enough or not.”

Now, maybe, just maybe, the Washington Nationals are going to get a chance to find out, to have the purely tough summer fun of discovering how good they are. For them, it’s the hardest, but potentially most rewarding, kind of labor. But for fans, it may be the ultimate fun: weeks or months, almost every day, of watching the team they’ve imagined for years actually get to play out its fate.

Nationals Park stopped playing A-ha's "Take on Me" during the seventh-inning stretch, and the Post Sports Live crew suggests some replacement songs. (Post Sports Live/The Washington Post)

For the past 15 months, Washington fans have waited to see the Nats when they were healthy and not miles behind in the National League East. It hasn’t happened. For two consecutive springs they have been one of the most injured contenders; when they finally had most of their team back late last season, it was too late to make up 141 / 2 games on Atlanta or pull out the wild card.

For the moment, the Nats are on the exact opposite end of the sport’s spectrum. They’re the rare team that, after being swamped by injuries to seven stars in April through June, now has its entire projected 25-man opening day roster in working order and is only a half-game behind Atlanta. The pendulum swings, the worm turns, what goes around comes around . . .

Oh, you get it. After more than 200 games of taking it from the baseball gods, and from themselves, the Nats have a chance to dish it back out. Actually, they already have been. After an ugly extra-inning loss May 28, followed by some internal and external tongue-lashings, the Nats have gone 21-11, the best record in baseball, and outscored foes by 49 runs — the rate of a 109-win team. It may have helped that Ryan Zimmerman came back June 3 after missing 44 games, as a left fielder. Leadership?

Someday, and this is almost a promise, Washington is going to look back on this July 4 and say: Remember when everybody was healthy? Remember when the five-deep rotation and the seven-deep bullpen were both probably in the top three in MLB? And together they had the best staff ERA in the game. Do you believe Doug Fister was called a “fourth starter” because Gio Gonzalez had been a 21-game winner, Jordan Zimmermann a 19-game winner and Stephen Strasburg was leading the league in strikeouts? That team even had spare parts at Class AAA, such as Blake Treinen, who fit in when needed.

Nobody has been amused this week at the fuss over Manager Matt Williams’s lineup decisions. But almost guaranteed, there’ll be a day when the Nats and their fans think, Oh, to have those “problems” again: whether to rest or bench Denard Span, Danny Espinosa, Jayson Werth, Adam LaRoche, Ian Desmond, Ryan Zimmerman, Anthony Rendon, Bryce Harper or Wilson Ramos because you’re allowed to play just eight guys at once. They even had a decent backup catcher, Nate McLouth to pinch-hit and guys such as Steven Souza at Syracuse, hitting .353, who couldn’t even get called up for one at-bat once the team was healthy.

Right now, the Nats lack an MVP-quality star in the center of their lineup, an offensive fulcrum who generates fear like Troy Tulowitzki, Mike Trout, Giancarlo Stanton, Andrew McCutchen, Paul Goldschmidt, Miguel Cabrera or a half-dozen others in baseball. That’s one reason they need their everyday lineup to be so close to full strength — a “long” lineup — to score 4.5 runs per game (top 10), rather than being hamstrung back to the 20th-best offense (4.0) if their lineup is a couple of hitters “short.”

But that’s about all they lack.

It is a temporary condition.

So enjoy it. Let the worrying take care of itself. In spring training the Braves lost two rotation pieces for the year in two days. Last week, the Cardinals sent two starting pitchers to the disabled list on the same day. On opening day, the Nats thought they were almost as intact as they are now with only Fister on the DL. It took Ramos seven innings to break his wrist with Zimmerman, Harper, Span, LaRoche and Gonzalez soon to follow to the injured heap. “Cheerful” is an endangered species in a 162-game season.

However, plenty of teams actually do stay quite healthy for memorable periods. For the next 100 games through the World Series? Unlikely. But the Cards had eight players who averaged 144 games last year — virtually perfect attendance at every position. When their fourth and fifth starters got hurt, the pitchers they called up (Michael Wacha, Joe Kelly) were better. The Red Sox had nine players last season who averaged 132 games each. And 51 of those “missed games” were just to use a backup catcher.

What a shock: The Red Sox and Cards met in the World Series. This season, they’ve had more injuries. Combined, they’re 84-87, and neither would be in the playoffs if they started now.

All fans yearn to see their team play one healthy chunk of a summer, so they can store it in their own baseball memory book. There, that’s what the real team, not some patched-together pressing-too-hard-to-compensate version of it, actually looks like. The 30,635-a-game who show up don’t need to know (spoiler alert) every plot twist through October. But how about just one flippin’ peek at the whole cast?

For a decade, D.C. fans followed the first-round drafts of Zimmerman, Harper, Rendon, Strasburg, Ross Detwiler and Drew Storen. They’ve watched trades for Gonzalez, Fister, Span, Ramos, Tanner Roark and Tyler Clippard that cost (in players who’d make the Nats’ roster now): A’s catcher Derek Norris. That’s all. The signing of Werth, LaRoche and closer Rafael Soriano blended with patient development of Desmond and Zimmermann, plus late-round draft steals of Craig Stammen and Aaron Barrett.

Would it really be too much to ask to watch ’em all play together for a while?

Just for the hot summer fun of it. (Please.)