National manager Dusty Baker, however, would not say who would start Games 2 and 3.
Baker said the decision hinges on the status of ace Max Scherzer, who tweaked his right hamstring during his last regular-season start. For the second day in a row, the two-time Cy Young Award winner threw on flat ground in the outfield but did not go through a bullpen session off a mound, which starters usually do two or three days before a game.
Left-hander Gio Gonzalez, who did throw a bullpen session Thursday, is the Nationals' other option for Game 2.
General manager Mike Rizzo said the team would not decide on a Game 2 starter until later Thursday.
Said Baker: "A lot of it depends on our evaluation of Scherzer.''
Because of days off in the schedule, whoever pitches in Game 2 could be available on regular rest to start Game 5, if necessary.
Asked whether that could be a factor in the decision of when Scherzer is used, Baker said: "Is that worth taking a chance -- and if you get past the first round, then are you jeopardizing the second round? So you have to kind of weigh both. But the health of Max, I think, is No. 1.''
Scherzer led the NL with 268 strikeouts this season and finished second with a 2.51 ERA, while leading the Nationals in wins at 16-6.
Strasburg is coming off a dominant regular-season finale in which he gave up only two hits in 7 2/3 innings against Pittsburgh on Friday. He retired the first 14 batters he faced in the 6-1 win.
Since returning from the disabled list Aug. 19, Strasburg has given up no earned runs in six of eight starts and has fanned 63 batters against only 10 walks. According to ESPN Stats & Information, his 0.86 ERA since the All-Star break is the second-lowest ever by a pitcher in the second half of a season (minimum of 10 starts), behind Arrieta (0.75 in 2015).
"This is what we brought him here for -- to be a No. 1 starter in the playoffs. He's been our horse,'' Rizzo said. "He has the repertoire, character and makeup to be a No. 1 starter.''
Strasburg, who went 15-4 with a 2.52 ERA and 204 strikeouts this season, made his only postseason start in 2014, when he pitched Game 1 of the NLDS against San Francisco.
"I'm excited for the opportunity to pitch in the playoffs again. It's one thing you really can't take for granted,'' Strasburg said, "and you've got to make the most of every opportunity you get.''
Information from The Associated Press is included in this report.