After a burst of roster moves in the past week — including the addition of three infielders and two relievers — here are two questions still facing the Washington Nationals: Who starts at third base on Opening Day? And who protects Juan Soto in the batting order?

There was once a way to answer both with one signing. The Nationals were interested in Josh Donaldson throughout this offseason, even putting a four-year, $100 million offer on the table for the third baseman. But in the past six days, as they sped through a long to-do list, the Nationals have all but moved on from Donaldson. Bringing in relievers Will Harris and Daniel Hudson and infielders Starlin Castro, Asdrúbal Cabrera and Eric Thames — and pledging about $25 million to them for next season — was a clear indication of that. Now they’ll have to get creative to fill some critical holes.

That’s where Castro becomes a major factor for 2020. He is not one of the club’s top hitters. That would be Soto, Trea Turner and, to a lesser extent, Howie Kendrick and Adam Eaton. Castro is not the Nationals’ best infielder. That is Turner. He was also not their biggest acquisition this offseason; one can argue that bringing back Stephen Strasburg, Kendrick and Hudson, and adding Harris, one of the best relievers on the market, were all more important moves.

But Castro brings versatility to the areas Washington needs it. He played second and third base for the Miami Marlins last season, and he even moonlit at shortstop, where he began his big league career with the Chicago Cubs. He rebounded from a rough first half to rake down the stretch. Whether he can protect Soto, or play every day at third base, only adds questions to the question marks. Yet he may emerge as the best answer — to one of those instances, or perhaps both — as the Nationals try to defend their World Series title.

This is what Castro said about his improved offense Tuesday, once his two-year, $12 million contract was official: “It’s been tough already ... so I just say: ‘Okay, just pull the ball. Try to do launch angle. Try to hit the ball in the air.’ And then see what happens.”

And this is what he said about what position he prefers, and the possibility of playing more third base: “It was kind of scary the first two games, then just started to feel comfortable out there. I feel really comfortable at second base, but I know I can play third, too.”

His second-half production showed that an adjustment to his approach and a tweak to his stance made a huge difference. Before the all-star break, Castro hit six home runs, struck out 64 times and had a .608 on-base-plus-slugging percentage in 88 games. After the break, he clubbed 16 homers, struck out 47 times and had an .892 OPS in 74 games. He realized he was hitting too many balls on the ground. He opened his stance a bit and moved his right foot back, committing to two tenets of the launch angle movement. Looking to pull the ball in the air went a long way.

If he unlocked something, and can stay on that track, he figures to fit well in the middle of Washington’s order. Soto, at 21 years old, is one of baseball’s best hitters, and he now has Washington’s most feared bat. He batted fourth last year and protected Anthony Rendon, the third baseman who signed with the Los Angeles Angels in December. There wasn’t a better 3-4 combination in baseball. But if Soto hits third now, and that is likely, Castro is the only everyday player who profiles well behind him. Kendrick, Cabrera and Thames are expected to be part-time players. If the Nationals bring back first baseman Ryan Zimmerman, a move they remain interested in, he would join a platoon, too.

The Nationals feel Castro’s best defensive position is second base and, if third base is filled internally, Cabrera and Carter Kieboom are options. But if Kieboom is not ready to go from top prospect to everyday player, and Cabrera regresses to the hitter who was released by the Texas Rangers last season, Castro could find himself with added opportunities at third. He appeared in all 162 of the Marlins’ games last season, played in 154 in 2018, and, barring injuries, will get a similar workload with Washington.

How it looks, and how it’s divided, will mean a lot for this team.

More on the Nationals: