However, this weekend, the intensity of the rivalry could reach another level.
Chicago (82-70) is battling for its postseason life -- and the job security of manager Joe Maddon could depend on the final standings -- as it prepares to welcome St. Louis (85-67) on Thursday night to open a four-game series.
The Cubs trail the Cardinals by three games for first place in the National League Central division with 10 games to play. Meanwhile, Chicago is even with the Milwaukee Brewers (82-70) for the NL's second wild-card berth, meaning those two teams would square off in a game No. 163 for the right to claim the second wild card if the season ended now.
Nothing is certain yet, of course, as the Cubs and Cardinals will play seven times in the final 10 games. Chicago could come out of the weekend with everything from a one-game lead in the division to a seven-game deficit depending on how the next four days shake out.
"It's just so weird how all this is coming together," Cubs third baseman Kris Bryant told the Chicago Sun-Times. "But it's in our hands here. If we do really well against them these last seven games -- obviously with the Pirates in between -- we would set ourselves up pretty good."
St. Louis and Chicago already have met a dozen times this season, with the Cubs going 7-5. That includes a 6-0 mark at Wrigley Field.
Or, from the Cardinals' perspective, an 0-6 mark.
But St. Louis is feeling good after winning two of three games against the Washington Nationals, including a 5-1 victory on Wednesday afternoon in which veteran starter Adam Wainwright outdueled St. Louis-area native Max Scherzer.
Wainwright said he and his teammates would carry their good vibes with them to Chicago.
"Now we go with a little momentum, we beat two very good pitchers (on the Nationals)," Wainwright told the St. Louis Post-Dispatch. "And now we've got to go up and beat those Cubs in Chicago. We haven't beat 'em all year in Chicago. We're going to beat 'em this time."
The Cardinals will turn to their hottest pitcher, right-hander Jack Flaherty (10-8, 3.05 ERA), who is slated to make his 31st start. He has been excellent since July 7, going 6-3 with a 1.07 ERA in his past 13 starts. Opponents are hitting .152 against him during that stretch.
In eight games (seven starts) against the Cubs in his career, Flaherty is 2-2 with a 3.60 ERA, including 1-1 with a 3.80 ERA in four starts vs. Chicago this year.
The Cubs will counter with their steadiest option, right-hander Kyle Hendricks (11-9, 3.26 ERA). He has won three straight decisions, including a strong effort his last time out as he limited Pittsburgh to one run on seven hits in six innings Saturday.
Hendricks is 8-2 with a 2.74 ERA in 17 career starts against the Cardinals. This season, he is 3-0 with a spectacular 0.39 ERA vs. St. Louis, with only one run allowed in 23 innings.
The Cubs know the pressure is on them to play catch-up. They believe they can do it.
"I think guys are ready to go," Cubs outfielder Kyle Schwarber told the Sun-Times. "We're in a good spot. We can control where we end up."
--Field Level Media