Nationals beat writer Adam Kilgore talks about whether Ryan Zimmerman will eventually return to third base when he rejoins the team. (Post Sports Live/The Washington Post)

On Thursday night, the Washington Nationals will make their first selection in the 2014 first-year player draft, the 18th overall. And like many teams, they face a fundamental dilemma: weighing the risk and reward of selecting an injured prospect.

The current draft class, Nationals evaluators say, is deep with hard-throwing pitchers and left-handed power bats. This year, however, several of those high-ceiling players are recovering from surgery or have dealt with injuries.

So how do the Nationals, an organization with a track record of taking chances on talented but injured players, decide whether an injured player with a high ceiling is a better pick than a healthier but perhaps slightly less talented player? It is a combination of shoe-leather scouting, calculated risks and the best available player on the board.

“You really do have to balance the risk and the reward,” General Manager Mike Rizzo said. “What we’ve looked at in the past is the upside has to really trump the risk of the player not coming back from injury. We really weigh elbow injuries a lot more favorably than shoulder injuries. A lot goes into the character of the player and the type of makeup that he has because the rehab process is not an easy. It’s not a simple one.”

The Nationals are picking in the first round for the first time in two years. Because they signed Rafael Soriano before the 2013 season, the qualifying offer attached to the closer meant the Nationals had to surrender their first-round pick to the New York Yankees.

This year, the Nationals have the eighth-smallest signing bonus pool at $5.275 million. And with $2.15 million allotted as a bonus for the 18th pick, the Nationals are in a position to scoop up injured talent passed over by other teams.

And they may be among the best-equipped teams to handle injured players. Three years ago, Anthony Rendon — rated as the top hitter in the draft and likely the No. 1 overall pick — was passed over by five teams, in part because of two ankle surgeries and a shoulder injury. The Nationals selected Rendon with the sixth overall pick, and despite another ankle surgery, he has been a mainstay on the roster since his call-up last summer.

Two years ago, fireballing high school pitcher Lucas Giolito was also considered a top overall pick before he hurt his elbow. The Nationals selected Giolito 16th overall. He later underwent Tommy John surgery and is dominating at Class A Hagerstown. Giolito felt comfortable signing with an organization that had helped Stephen Strasburg and Jordan Zimmermann return from their Tommy John surgeries.

The Nationals’ rehab staff has “a track record of success,” said Kris Kline, an assistant general manager and vice president of scouting operations. “So that gives you much more of a comfort level of taking somebody like that even though you’re not going to get them for a year.”

But with those successes, there have been misses, such as left-handed prospect Matt Purke, who had shoulder issues when he was drafted in the third round of the 2011 draft. Purke, who was signed to a major league deal worth about $4 million, had shoulder surgery in 2012 and then Tommy John surgery last month.

“You’re not going to get them all right,” Kline said. “It’s impossible. You work your tail off and you try. You try to get as many right as you can, and that’s part of the job. . . . When your doctor gives you the green light and you have Riz, who is aggressive and not afraid to make mistakes, it’s a pretty good recipe for success. And it has been so far.”

Top-flight pitching prospects in this year’s draft — Jeff Hoffman (East Carolina) and Erick Fedde (UNLV) — saw their stocks tumble last month when both right-handers underwent Tommy John surgery. Both could now be mid-first-round picks and fall to the Nationals.

When evaluating amateur players, Kline said Nationals scouts identify players who are high injury risks. Kline said the Nationals stay away from pitchers with extensive shoulder injuries or other ailments that aren’t easily fixed. For example, pitchers with clean mechanics are ideal targets over those with flawed mechanics — unless their stuff is already so dominant that it is worth taking the risk and changing their delivery. “And then sometimes there’s no rhyme or reason why [they get hurt],” Kline said.

Area scouts, the ground-level talent evaluators who see the players most often, gather as much medical information as possible on potential picks from coaches, players, advisors and the scouting bureau. Players’ camps can be tight-lipped, Kline said, but “in the end, it’s our responsibility to find out whatever we can about that player.” A team’s doctor can’t perform a physical until after a player is drafted.

“We do know and we better know everything about that player,” Rizzo said. “We’ve seen these guys for a number of years. The area scouts are the anchor of our scouting department. They know the ins and outs of every player in their territory. We have the health histories, the physiological testing and a myriad of other checkpoints before we consider taking a player.”

When it comes to picking the player, the Nationals have to make a calculated risk and weigh many factors. “To break a tie, if you’re thinking about taking a healthy player and a hurt player, the hurt player would have to be 10 shoulders better than the other guy,” Kline said.

Some officials within the organization would prefer to avoid picking an injured pitcher passed over by other teams. As a result, the Nationals instead could select a hitter, and they have scouted many, including switch-hitting junior first baseman Casey Gillaspie (Wichita State) and left-handed-hitting first baseman A.J. Reed (Kentucky), both regarded as mid-to-late first-round talents. Gillaspie, the son of former all-American Mark and brother of Chicago White Sox third baseman Conor, hit 15 home runs and had a 1.202 on-base-plus-slugging percentage this season. Reed, a junior, led NCAA Division I baseball with 23 home runs and a .735 slugging percentage in the regular season.

The Nationals may have a dearth of left-handed power hitters in the system, but they insist their decisions Thursday will be motivated by selecting the best player possible, while also weighing the injury considerations.

“We never go need,” Rizzo said. “I’ve never drafted for need since I’ve been doing this. It is best player available that gives us the best chance to have an impactful player in every round.”