It hasn’t even been a week, and it’s already time to worry. Was Anthony Rendon absent from the Capitals game and the White House visit because he already has left the World Series-winning Washington Nationals behind? Was Stephen Strasburg’s decision to opt out of his contract an opt-out on Washington as a place to play?

The confetti hasn’t all landed on Constitution Avenue, and the concerns about who will be a Nat next spring are raw. With baseball’s free agency underway, the long, slow process of building another team that could contend for — it still feels ridiculous to type this — another championship is already beginning.

For fans, this is emotional. For players and the team, it is financial. Nationals fans would love for Rendon’s heart to be filled with such warmth about Washington and what this group accomplished together that he would just sign the offer the Nats already extended him: seven years for $210 million to $215 million. It doesn’t work that way.

So let’s try to piece together what we know and what we don’t, and get ahead on (re-)building a championship-caliber roster.

When General Manager Mike Rizzo and his staff went about building the 2019 team, they had dueling priorities: assemble a squad that could win a division (or more) but stay below baseball’s competitive balance tax threshold, the payroll number above which teams are taxed. Guess what? They did it! The Nats’ payroll for 2019 did not exceed $206 million. That matters going forward.

Strip down what comes off the books for 2020, because that matters, too. Rendon, Strasburg, Ryan Zimmerman, Yan Gomes, Matt Adams, Brian Dozier and Howie Kendrick are free agents. Some could return. Others definitely will depart. But that’s roughly $85 million off the books right there.

(Note: I say “roughly,” because some of this is unknowable without seeing the open books. Max Scherzer, for instance, signed a seven-year, $210 million deal with the Nationals back in 2015. The math seems easy. He must count $30 million toward the tax threshold every year, right? Well, he doesn’t. According to two people with knowledge of Scherzer’s contract, he is due $35 million in 2020, but all of that money is deferred. Sort it all out, and Major League Baseball counts Scherzer at about $28.7 million. The financial semantics in all this leaves us doing educated guesswork, nothing more.)

Washington’s big-ticket items are, of course, Strasburg and Rendon. Let’s take them in that order.

Strasburg’s seven-year, $175 million extension kicked in in 2017 and contained the opt-out that he exercised over the weekend. The view of the Strasburg camp, led by agent Scott Boras, is that the Nats got him at a bargain rate — a claim that holds up given he just led the National League in innings, was named the World Series MVP and had a 3.15 ERA over those three seasons.

Now, to retain him, the Nats will have to pay him more like they had competition from the other 29 teams, which they will. Scherzer turned 31 in the first year of his deal with the Nats. Strasburg will turn 32 in the middle of next summer. It’s not unreasonable to think something similar to Scherzer’s contract — seven years, $210 million — would be what Boras is seeking. Strasburg’s a year older, so maybe the Nats want one fewer year.

Either way, work something out. Strasburg moved his family here year-round. Over last winter, he worked out at Nationals Park and threw bullpen sessions at Georgetown. He is comfortable, and that matters. It’s hard to imagine Strasburg asking Boras to go for the biggest paycheck, regardless of club.

This is a problem, but it seems solvable. Prediction: Strasburg remains a National.

Rendon’s situation is harder to decipher, and decidedly so.

Start with this: The eight-year, $260 million deal signed by Colorado third baseman Nolan Arenado before this season no longer seems so out of Rendon’s reach. Yes, Rendon turns 30 next year, and Arenado was just 28 in the first year of his contract. But after Rendon’s .328/.413/.590 postseason — which followed a .319/.412/.598 regular season in which he led the NL in RBI — an average annual value of $35 million becomes more realistic.

The question for the Nationals: Can they move up from their current offer? Would they agree to not defer money? That’s a tactic they use in almost all negotiations but one that does not thrill Rendon, according to multiple people familiar with his thinking.

And would the Nationals — at somewhere around $65 million annually — be able to bring back both Strasburg and Rendon?

The prediction: Rendon goes elsewhere.

It’s such a complex equation, because if you look beyond next year — in some cases well beyond — there would be potential extensions for shortstop Trea Turner and outfielders Juan Soto and Victor Robles. That’s the best part of the Nats’ roster construction: Soto and Robles aren’t even eligible for arbitration yet, and Adam Eaton just had a team-friendly $9.5 million option picked up for 2020, so the entire starting outfield will cost around $11 million. That leaves flexibility elsewhere.

Another question: Will the ownership of the Lerner family allow Rizzo and his staff to exceed the tax threshold again? This seems major. It’s actually kind of minor.

I’m a big believer that the dangers of the tax are overstated by clubs. Exceed the threshold three years in a row, and a club is taxed at a 50 percent rate. But that’s just on the overage, the amount by which it exceeds the threshold. So for instance, in 2020, when the threshold bumps up to $208 million, a third time violator that spends $220 million in payroll would cost itself $6 million in taxes. It’s not a huge deal — and it’s even less of a problem for the Nats. Because they were under the threshold in 2019, their tax rate resets. The next time they blow past the limit, they would be taxed at just 20 percent.

All of which is a long-winded way of saying if the goal is to compete for a title, don’t let the competitive balance tax be an impediment.

There are other issues. In that $85 million or so that will come off the books, the Nats must find a first baseman. Club officials said during the postseason they would be open — very open — to bringing back both Zimmerman and Kendrick to share, in some fashion, the first base job, even though one is 35 and the other is 36 and they both hit right-handed. Even if Strasburg comes back, they’ll need another starting pitcher. (Austin Voth? Joe Ross?) There are bullpen issues to rectify, but when has that not been the case?

The point: The offseason and the business it entails are here. It’s unlike any the Nationals have conducted before, and not just because they have two homegrown stars as free agents. For the first time, they’re trying to reassemble a World Series winner. For the team, that involves financial and baseball evaluations. For the fans, it involves emotions. Less than a week after winning the World Series, that’s hard.