Sammy Solis (

Wednesday will bring one of those small deadlines that help shape baseball’s offseason. The Nationals, like all 30 teams, must set their 40-man roster and protect players they wish to make ineligible for the Rule 5 draft, which takes place Dec. 12 in Orlando, the final day of the winter meetings.

Two kinds of players can be plucked from clubs in the Rule 5 draft: players who have played four seasons and debuted as a professional after they turned 19, and players who were 18 at their debut and have played five seasons. For this year, essentially, that means players drafted out of college in 2010 and players picked from high school in 2009. Teams can prevent opposing clubs from taking its players by adding them to their 40-man roster.

If Team A chooses Team B’s player in the Rule 5 draft, Team A must pay Team B $50,000 and carry the player on their active roster all season in order to keep him. If Team A does not keep the player on their roster all year, the player goes back to Team B, which is free to keep that player off its 40-man roster. Team A also gets a $25,000 refund.

The Rule 5 draft typically produces minor ripples, but occasionally gems can be unearthed. Roberto Clemente famously went to the Pirates in the Rule 5 draft. Dan Uggla was a Rule 5 player, and so was Jesus Flores. The Nationals lost Michael Martinez to the Phillies in the Rule 5 draft, and for a few seasons he served as Philadelphia’s speedy, no-hit utility man.

Last year, two Nationals added right-handed pitchers Nate Karns and Erik Davis to prevent other teams from taking them in the Rule 5. Two unprotected prospects were taken in the major league portion of the draft. The Tigers took Jeff Kobernus, and the Rockies picked Danny Rosenbaum. Both teams returned them late in spring training. Kobernus ended up making the Nationals’ 40-man roster when they promoted him to the majors. Rosenbaum spent all year at Class AAA Syracuse.

Presently, the Nationals have 39 players on their 40-man roster. For the Nationals to add more than one player, they would have to try to pass one of their current players through waivers or swing a trade. If they wanted to cast off a player Tyler Robertson, a big lefty who missed almost all of last year with injuries, would be a candidate to sneak through waivers.

The Nationals will almost certainly add left-hander Sammy Solis, a 25-year-old who performed well in the Arizona Fall League to cap a season in which he returned from Tommy John surgery. General Manager Mike Rizzo recently broached the idea of using Solis, one of the Nationals’ best starting prospects, as a big league reliever this season.

The Nationals may be tempted to add two others. Nationals officials rave about center fielder Michael Taylor, whom they picked in 2009 out of high school. Taylor hit .263/.340/.426 as he repeated Class A Potomac in 2013, slugging 10 homers and 41 doubles.

Nationals officials believe Taylor, 22, would be an elite defensive center fielder in the majors right now, and they envision him developing into a solid power hitter. If they do not add him, it will be because he’s too raw for another team to carry him in the majors. Taylor struck out 133 times and drew just 55 walks, and he has never played above Class A.

Right-handed reliever Aaron Barrett also merits consideration. A ninth-round pick in 2010, Barrett pitched last year in the Arizona Fall League. This year in Harrisburg, Barrett, 25, punched up a 2.15 ERA and a 1.093 WHIP in 51 appearances. He struck out 69 and walked 15, relying on an excellent slider that allows him to pitch with a fastball in the 90-92 mph range. The Nationals probably already have enough relief pitching on their 40-man roster to let Barrett dangle and hope he goes unpicked or gets returned.

An original version of this story stated the Nationals’ 40-man roster was presently full.