WASHINGTON -- Josh Donaldson has agreed to a deal with the Twins.

Donaldson, who was the closest player to a pure replacement for the Nationals for Anthony Rendon on the open market, is heading to Minnesota on a four-year, $92 million deal, a source told MLB.com’s Mark Feinsand on Tuesday. Now, the Nationals must find another way to fill their hole at third base.

There are still several avenues for the Nats to explore. They could focus on the trade market, with a slew of top names floating in rumors, or hope to get the production from their in-house options, which is the more likely option.

Asked about the Nationals’ hole at third base during Winterfest last Saturday, general manager Mike Rizzo rebuffed: “We don’t see it as a hole. We see it as a strength.”

Who can step up that’s on the roster now?

The Nationals began preparing for a Plan B with the signing of Starlin Castro and the re-signing of Asdrúbal Cabrera at the beginning of the month. Both do not have the offensive punch to fully replace Rendon’s production in the lineup -- maybe the signing of Eric Thames can help in that regard -- and indications are that the Nationals signed Castro with the expectation that he'll play second base.

But intentions can change. If a trade does not occur, expect Castro and Cabrera to interchange at third base and get involved in the second-base mix with Howie Kendrick.

This could become moot, however, if prospect Carter Kieboom has the Spring Training the Nationals are hoping for.

“I think he’s very, very close to Major League ready,” Rizzo said in December. “If I feel he’s ready to make the club -- and make an impact on the club -- he’ll certainly get an opportunity.”

Should Kieboom, the Nationals' No. 1 prospect per MLB Pipeline, impress during February and March, it could be difficult for the club to prevent him from opening the year at second base, or perhaps third, where he started to play near the end of the 2019 season. That would allow the 35-year-old Kendrick and the 34-year-old Cabrera to get more days off throughout the season.

Who could be targeted outside the organization?

There has been plenty of buzz on the trade market this offseason, but not too many deals have been completed. The Cubs' Kris Bryant, the Rockies' Nolan Arenado and the Mariners' Kyle Seager are the third basemen who have been involved in rumors.

While Arenado would be the closest thing to a pure Rendon replacement, Bryant may be the most logical fit. The 28-year-old former National League MVP Award winner has two years left on his contract and is the most affordable option of the group, set to earn $18.6 million in 2020. But the Cubs are expected to ask for a big haul in return, and Washington has been reluctant to part ways with players like dynamic outfielder Victor Robles.

Don’t count out Rizzo, who has made his mark in D.C. with crafty trades to plug in holes while concurrently maintaining a minimal teardown of the Major League roster. If there’s a name being floated around that makes sense for a team in 2020, expect the Nats to be in the conversation.

What other options are there?

As previously mentioned, the Nationals have been a pretty crafty bunch under Rizzo when it comes to under-the-radar moves. Trea Turner was acquired as a player to be named later via trade. The players they gave up in separate trades for Tanner Roark, Denard Span and Wilson Ramos -- all solid players for the Nats -- never really broke out after leaving Washington.

Maybe the resolution the Nats have in mind does not come at third base. Perhaps they'll upgrade a different area where there is less offensive firepower on their roster. Outfielders Marcell Ozuna and Nicholas Castellanos are both still on the free-agent market and could help fill the Rendon void. The Nats have a crowded outfield, but if the right move is there, perhaps they consider shifting things around and settling for more average production at third.

No matter what moves the Nationals decide to make -- or not make -- they weren't tied down while awaiting Donaldson's decision. They’ve improved their bullpen by signing Will Harris and bringing back Daniel Hudson. Plus, they improved their infield depth with the additions of Castro and Cabrera.