Hairston didn't make it because Ryan Zimmerman will be coming off the bench. Zimmerman may start if left-hander Madison Bumgarner is on the hill for the Giants. Detwiler and Hairston will be available if the Nationals make it to the NL Championship Series.
"With regard to Det, for the last months of the season, we had three lefties in the bullpen. We decided to go with two," Nationals manager Matt Williams said. "And certainly, [Thornton] has been throwing the ball well. Jerry, over the last month, has thrown the ball exceptionally well. It is not an easy decision, by any stretch. We decided to go with two lefties and had to make that [decision].
"With regard to Scott ... Zim will be coming off the bench a little bit for us. That is kind of our option, our first option [for a] right-handed [hitter] off the bench in that regard. We wanted a lefty; unfortunately, it doesn't leave room for Scott."
Soriano, part of an eight-man bullpen, would likely come in at the start of an inning. The Nationals had no intention of taking him off the roster, even though he was shaky after the All-Star break. Soriano was 3-1 with five blown saves and a 6.48 ERA in the second half. It didn't help that he had problems with his slider and mechanics. After the closer role was taken away from him and given to Drew Storen during the month of September, Soriano was uneven at best.
Williams said the team still believes in Soriano.
"[Soriano] has everybody's confidence. It never wavered," Williams said. "Our options at the back of the bullpen -- we have multiple guys who have closed games. Sori is one of them; [207 career] saves is a lot. He is one of the reasons why we are here. [He was] the premier closer in the first half of the season.
"[Soriano] went through mechanical issues and has worked diligently to resolve those. I think he is where he needs to be. [We] gave him opportunities late in the season to pitch, and he pitched well."
Catcher Jose Lobaton, infielders Danny Espinosa and Kevin Frandsen and outfielder Nate Schierholtz also made it onto the NLDS roster as reserves.
The Nats have announced Stephen Strasburg, Jordan Zimmermann and Doug Fister as starters for the first three games. Gio Gonzalez would likely start a Game 4 on Tuesday (if necessary), with Tanner Roark saying Thursday he expects to work out of the bullpen. The rest of the relief corps includes righties Aaron Barrett, Tyler Clippard, Craig Stammen and Storen.