In the case of the Cubs, Arrieta's availability could be a best-case scenario as he now will pitch a bullpen session Wednesday instead of a simulated game.
"It's just an indication we don't want to push him right now," manager Joe Maddon said of Arrieta, who missed 21/2 weeks because of a Grade 1 right hamstring strain and admittedly altered his delivery during his last start on Sept. 26 to compensate for the lack of full strength in his leg.
"We thought we could control it more in a (bullpen session) as opposed to a 'sim' game, which we didn't think was that impactful," Maddon said.
Maddon replied "no" when asked whether this will affect Arrieta's chances of making the NLDS roster, adding that he didn't aggravate his injury in his last start.
But if Arrieta is deemed not healthy enough to pitch, that could open a spot in the rotation for John Lackey, whose status hasn't been determined yet, Maddon said.
Lackey, 38, has made 446 starts and only two relief appearances during his 15-year major league career.
Meanwhile, Scherzer plans to test his right hamstring Wednesday in a bullpen session. Scherzer left his final start of the regular season Saturday with a hamstring issue.
"Oh, I'm pitching in the NLDS," Scherzer said. "I'm pitching in the NLDS."
But Stephen Strasburg, who threw a bullpen session Tuesday, appears lined up to start Game 1 on Friday in Washington.
"We feel like the pressure is on them because we know what we're capable of and excited," Zobrist said. "We weren't satisfied just because we won last year. We're excited to get it on again and make a great run."
The Nationals have lost three NLDS in the previous five seasons, while the Cubs won three consecutive elimination games to win the 2016 World Series.
"We have the relevant experience to know that in those moments there's nothing we're going to back down from or cower at," Zobrist said. "We know there are moments in the postseason you're tempted to put your head down, but I don't think this group will do that. We haven't done that in the past."
Bunt work: The Cubs worked on situational bunting during their simulated game that relievers Carl Edwards Jr., Hector Rondon, Pedro Strop, Jen-Ho Tseng and Rob Zastryzny pitched.
Another workout is scheduled for Wednesday before departing for Washington.