The Washington Nationals are World Series champions, and while they’re celebrating beating the Houston Astros in Game 7 on Wednesday night, welcome to what figures to be another exciting Yankees offseason.

The Yankees’ winter wish list surely includes starting pitching upgrades, and this year’s free agent market will provide plenty of good-to-great rotation options, most notably Astros co-ace Gerrit Cole.

Here is everything Yankees fans need to know about free agency:

-- The offseason fun begins Thursday with the start of a five-day free agent filing period.

-- The Yankees will have at least seven and as many as eight of their players file for free agency. The seven guarantees are shortstop Didi Gregorius, outfielders Brett Gardner and Cameron Maybin, catcher Austin Romine, relievers Dellin Betances and Cory Gearrin, and designated hitter Edwin Encarnacion, who was bought out $5 million instead of having a $20 million club option for 2020 exercised. Also, closer Aroldis Chapman can join the market by opting out of the final two seasons and $30 million of his five-year, $86-million contract.

-- Thursday is the start of five-day quiet period that runs through 5 p.m., Monday in which the Yankees (and every other club) have exclusive rights to negotiate new contracts with their free agents. The Yanks probably will working hard during this time trying to re-sign Gardner for sure and maybe also Betances, Romine and Gregorius. GM Brian Cashman also probably will engage with Chapman about adding years to his existing contract.

-- Chapman has until Saturday to opt out of his contract. Ken Rosenthal of the Athletic reported in July that Chapman “one million percent” will opt out. According to a report this week by Mark Feinsand of MLB.com, an unnamed major league executive predicted Chapman would land a four-year, $60-million contract on the open market that would double the years and cash remaining on his current pact.

-- The official free agent signing period begins when the quiet time ends Monday at 5 p.m. This is when the Yankees can reach out to Cole with an offer. For what it’s worth, we’re hearing the Los Angeles Angels are the favorite to sign Cole, who grew up near Anaheim and reportedly is intrigued about playing close to home.

-- The Yankees (and every other club) also have until Monday at 5 p.m., to decide whether to offer one-year qualifying offers to their free agents. The qualifying offer was $17.9 million for 2019 and will drop to $17.8 million this year. Qualifying offers guarantee draft pick compensation to a team losing a free agent to another club, which also would forfeit a draft pick. The only Yankees free agent whom for sure would get a qualifying offer is Chapman, but Gregorius would be a strong candidate as well.

-- Monday at 5 p.m., also is the deadline for the Yankees to make a decision on Encarnacion, who almost certainly will be bought out.

What can we expect from the Yankees this winter?

Cashman says the Yankees’ offseason plan will be to improve a club that won 103 games this season before losing to the Astros in the ALCS, and that quest probably will include making offers to free agents.

“I think we’re always aggressive and trying to attack areas that need improvement and it just comes down to what’s available in the marketplace,” Cashman said.

Randy Miller may be reached at rmiller@njadvancemedia.com. Follow him on Twitter @RandyJMiller. Find NJ.com on Facebook.