Following a 2-1 victory on Monday that provided the Cubs with a 2-1 lead in the best-of-five series, Arrieta has the chance to propel Chicago into a third straight NL Championship Series appearance.
In the back of his mind, though, Arrieta understands the Tuesday start could represent the final time he takes center stage for the home team at Wrigley Field.
Arrieta, who was slowed by a right hamstring injury late in the regular season, insists the ailment will be a non-issue. He recently threw two successful bullpen sessions.
Given his free agent status when the season ends, Arrieta acknowledged Monday that his time with the Cubs may be drawing to a close.
He plans to make the most of every opportunity, starting Tuesday.
"(I'm) just trying to take everything in (and) look around a little bit more trying to, you know, kind of capture some mental images of Wrigley and the fan base and my teammates," Arrieta said Monday. "(I will) just to try and remember as much as I can about these last couple weeks -- if it's my last time in this uniform."
Arrieta dropped his only decision against the Nationals this year and is 1-2 with a 5.48 ERA in nine career starts against Washington.
Like Nationals ace Max Scherzer, who no-hit the Cubs for the first 6 1/3 innings on Monday, Arrieta will make his first start of the postseason after using a few extra days to strengthen his hamstring. Arrieta hasn't pitched since Sept. 26, and he missed 2 1/2 weeks after straining the hamstring during a start on Sept. 4.
He will face a potent Nationals lineup that Arrieta knows he will have to be careful with, but one that again struggled to score runs on Monday. Arrieta said his goal will be to pitch as deep into the game as possible.
Scherzer, who was dealing with a right hamstring injury, said Sunday he felt comfortable throwing 100 pitches. Scherzer threw 98 on Monday and allowed just one hit.
Arrieta won't worry about numbers.
"Pretty much all bets are off in the postseason," Arrieta said. "But every time I toe the rubber, I'm trying to do my best to finish that game."
Nationals right-hander Tanner Roark will face Arrieta in a setting with which he is well-acquainted. Roark, a native of suburban Wilmington, Ill., made his first trip to Wrigley Field as a youngster. Roark is 4-2 in seven career starts against the Cubs and is 1-0 with a 2.84 ERA against Chicago this season.
Roark called the experience of pitching at Wrigley "surreal" and knows he will have to channel his emotions as much as possible -- especially with the Nationals facing elimination.
"(You've got to) hold the nerves in, hold the anxiousness and all that stuff in, and just let it come and let it happen," Roark said on Monday. "And that's what you've got to let it do."
The Nationals, who have scored seven runs in three games, will have to produce more if they hope to extend their season. Washington's only run Monday was set up two Chicago errors.
"We know (Game 4 is) right around the corner, and our back's against the wall," Nationals manager Dusty Baker said after his team's Monday loss, "so we've got to get them tomorrow. We've got to get those hits, and hopefully (the Cubs) don't."