Manager Joe Maddon will meet with the staff, including president of baseball operations Theo Epstein and general manager Jed Hoyer, to discuss their options. Jon Lester or Kyle Hendricks will likely start the first game of the best-of-five series.
"We're going to sit, we're going to talk," Maddon said Sunday. "I have my ideas, I know [pitching coach Chris Bosio] has his, I know Theo does, [bullpen coach] Lester Strode does. Listen, you could sway me in that meeting also if you give me reasons as to why I'm wrong."
The Nationals' Max Scherzer was expected to start the opener, but he came out of his start Saturday with what the right-hander called a minor right hamstring tweak.
"The 'tweak' as it's defined by the American Medical Association -- we all try to play semantically with injuries," Maddon said. "I have no idea what a 'tweak' is. A tweak could be a sprain or a strain, but I love the word 'tweak.'"
The Cubs' rotation was in flux because Jake Arrieta is questionable due to a hamstring issue. Arrieta will throw a simulated game Wednesday to test his leg.
"Hammies are funny," Maddon said. "If it's just a cramp [for Scherzer], that's something entirely different. If it's an actual injury to it, it could be a Grade 2 tweak."
The Cubs know they face a formidable opponent in Scherzer, who won the 2016 NL Cy Young Award, beating the Cubs' Lester and Hendricks.
"First of all, Mr. Scherzer is one of the best that I've ever seen," Maddon said. "When this guy is on, it's difficult and you have to pitch a little bit better than him and that's really going a long ways.
"The comfort is that you have the guys you want out there versus him -- those are things that will work in your favor," Maddon said. "But when this guy is on, I don't care who you're throwing up there at the plate, this guy is that good. You've just got to look for that edge in the game."
• Last year, the Cubs posted the best record in the Major Leagues, and this year, they've had to battle to repeat as NL Central champs. What's different?
"The part that feels different to me ... is that we know how to do this," Maddon said. "I'm going to have a meeting on Tuesday [with the players] and I intend it to be very brief. There's nothing I can say that will be stirring, motivational, substantive in the sense that it will change their minds about anything. I want our guys to go out and continue doing what we've been doing since the All-Star break. No different."
The Cubs entered Sunday's regular-season finale against the Reds with the best record in the NL since the All-Star break at 49-24.
"I don't anticipate any kind of nervousness or over-anything," Maddon said. "I anticipate our guys going out and playing the game that we've come to play. That's what I'm looking forward to watching.
"Since the All-Star break, we've done as good as anybody -- except Cleveland," he said of the Indians, who boast the best record in the Majors since the midway point.
Carrie Muskat has covered the Cubs since 1987, and for MLB.com since 2001. She writes a blog, Muskat Ramblings, and you can follow her on Twitter @CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.