Ian Desmond snags a line drive last Sunday in the Nationals’ 3-2 win over the Orioles. (Katherine Frey/The Washington Post)

The end of a relationship, in professional sports or otherwise, so often brings with it the assignment of blame. If one party had not been so stubborn, it wouldn’t have to end. If the team hadn’t been so cheap, it wouldn’t have to replace a perceived cornerstone. If the player hadn’t been so greedy, a beloved star wouldn’t have to leave. The end provokes. It bullies you into picking a side.

The urge to blame will become a temptation once another half season, plus a likely playoff run, comes and goes. Shortstop Ian Desmond and the Washington Nationals almost certainly will part ways once Desmond’s contract expires, the conclusion to a partnership that began in 2004, when the Nationals were not even the Nationals yet. Fight the impulse to point fingers. Appreciate Desmond while he’s still here, and prepare to say farewell without animus. Remember that sometimes both sides are faultless, that goodwill can remain intact and that this is one of those times.

Desmond and the Nationals made a beautiful pair. Desmond, enduring the worst season of his career in his walk year, was drafted by the Montreal Expos and grew into part of the franchise’s soul, a vivid symbol of where they came from and what they became. He won three Silver Sluggers, made an all-star team and rooted himself in the community. He loves the Nationals, always will. Under General Manager Mike Rizzo, the Nationals stuck with Desmond during lean years in the minors and early struggles in the majors. They gave him time, trusted his talent and let him flourish from an 18-year-old kid into a 29-year-old man.

It seemed for so long that Desmond’s time in Washington didn’t have to end — and wouldn’t. No less an influence than Marla Lerner Tanenbaum, daughter of Ted Lerner, who runs the Nationals Youth Baseball Academy that Desmond helped cultivate, has called Desmond her favorite player.

Business intervened. Two winters ago, Desmond made a bold, calculated decision that, at the time he made it, showed a savvy understanding of baseball’s economics and was absolutely justified. The Nationals held firm to their valuation of Desmond and executed a series of shrewd trades that set them up with a multifaceted, appealing future outlook at shortstop. They both did what they had to do.

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The beginning of the end came in the winter before the 2014 season, when the Nationals offered Desmond a seven-year, $107 million contract extension. Desmond rejected it. The Nationals and Rizzo, for two years, stuck to their vow that the offer was final. The sides settled on a two-year, $17.5 million pact before 2014, which made the 2015 season the possible endpoint. That possibility has moved past likelihood and close to cemented.

It has played out, for Desmond, in horrific fashion. He spent the season’s first half suffocating his free agent value, opening the year with an alarming spate of errors and hitting .211 with a .589 on-base plus slugging percentage even as his defense normalized. Teammates admire the steadiness he brings to his job every day, but by performance he has been one of the worst regulars in baseball.

It has played out, for the Nationals, just as they designed. This winter they traded for Yunel Escobar and minor leaguer Trea Turner and held on to Danny Espinosa. Escobar has been a solid starter at third base. Turner has scorched the ball and rocketed up prospect rankings while blowing through Class AA Harrisburg to AAA Syracuse. Espinosa experienced a career renaissance, bouncing around the diamond and becoming a hugely valuable, versatile fill-in. Turner is the high-ceiling, long-term prize, a potential star. Either Espinosa or Escobar could start at shortstop on opening day 2016 if the Nationals choose to further season Turner. Either way, the Nationals have given themselves options and depth at a tough position to fill.

Given the results of the past three months, it is easy to fault Desmond for overvaluing himself, to call him greedy, to scream about the folly of turning down $107 million. It’s also overly simplistic and wrong.

During negotiations, Desmond was one of the best players at a premium position. From 2012 through 2014, Desmond totaled the most wins above replacement among big league shortstops. One agent unaffiliated with Desmond said his free agent contract would likely fall just shy of the range of center fielder Jacoby Ellsbury — another power hitter at an up-the-middle position.

In December 2013, Ellsbury signed with the New York Yankees for $153 million over seven years. Given the structure of the Nationals’ offer, Desmond would have made $90 million over the five years following his free agency eligibility.

Yes, $90 million is a lot of money to turn down. But Desmond didn’t make a decision in a vacuum. In his profession, at that time, he was worth more. (Save the caterwauling about how much money ballplayers make. The money is there; it’s going in their paychecks or it’s staying in the owner’s pocket.)

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The Nationals didn’t lowball Desmond; they offered him the chance to sign a team-friendly deal while sacrificing money for risk. Given the information available and his priorities, Desmond made a sound financial decision.

“If you said, ‘Hey, Ian, we want you to play here for the rest of your career.’ Okay. Yeah, absolutely. Duh. Where do I sign up?” Desmond said in March 2014. “At the same time, there have been a lot of people that have come through this game that have sacrificed a lot for us, the players that are coming through now. I don’t want to sign a deal — and this isn’t to say they’ve offered me this — but I don’t want to sign a deal that is so bad that a future shortstop gets screwed because I signed a terrible deal. I’m not going to be that guy, that kink in the chain. I’m going to get a fair deal, or I’m just going to wait.”

Desmond could not have known his performance would suddenly, inexplicably crater. Even now, Desmond could reap a contract similar to what the Nationals offered. If Desmond produces a second half in line with his previous three seasons, proving the first half was only a nightmarish blip, he’ll have ample suitors.

The scarcity of shortstops is too stark for Desmond’s market to dry up. Look at Desmond’s fellow free agent shortstops: the biggest names are Alexei Ramirez, Asdrubal Cabrera, Stephen Drew and 37-year-old Jimmy Rollins. Would a GM rather bet on that motley bunch or a Desmond bounce-back?

Desmond is the kind of player who’s thinking about this as little as possible, who wants to bring the only city he has ever played in a championship. The Nationals and Desmond still have one more half season before their almost certain parting. The end doesn’t have to be ugly. For Desmond and the Nationals, it shouldn’t be.