Cincinnati now sits atop the National League Central, and increased its lead on third-place St. Louis to 3 1/2 games.
"People are excited, and they should be, and hopefully they stay that way to the end," Reds manager Dusty Baker said. "You play better in front of large crowds, especially at home. This is a big series for them and us. You want to start the second half like this against a team that's chasing you, and hopefully we can put some distance on them this weekend."
Johnny Cueto was scratched from Sunday's start due to a blister on his right index finger, and Homer Bailey will take the hill in his place. Bailey was slated to throw on Tuesday against the D-backs.
That is likely an advantage for the Cardinals, as Cueto's 2.39 ERA is the fifth best in the Majors, and he hasn't allowed more than three runs in a start since May 25. Bailey owns a 4.14 ERA this season, and allowed four runs on six hits in 5 2/3 innings against St. Louis on April 9.
Current Cardinals are batting .330 against Bailey, and Matt Holliday and David Freese have each homered twice against him.
St. Louis starter Jake Westbrook opposed Bailey on April 9, allowing one unearned run and three hits over seven innings for the win in his first outing of the season. He's 3-2 with a 2.95 ERA, 21 strikeouts and seven walks in his last six starts.
Cardinals: Berkman activated off DL
First baseman Lance Berkman was activated from the disabled list on Saturday, and struck out in a pinch-hit at-bat in the seventh inning in his first game back since May 19. The Cardinals anticipate Berkman will start on Sunday.
Berkman underwent right knee surgery less than a week after sustaining the injury, and recovered quicker than expected. The Cardinals do not plan on playing him on back-to-back days for a while, and will spread out Berkman's playing time since he opted out of a Minor League rehab assignment.
Outfielder Shane Robinson was optioned to Triple-A to make room for Berkman on the 25-man roster.
The Cardinals signed free agent Brian Fuentes to a Minor League contract on Saturday. The 36-year-old left-handed reliever will report to the club's Gulf Coast League affiliate on Sunday to begin a predetermined seven-day Minor League program.
Fuentes was released by Oakland earlier this month, and has not pitched since June 30. The four-time All-Star was 2-2 with a 6.84 ERA in 26 games with the Athletics this season.
Reds: Ludwick contributing offensively
After beginning his season batting .201 through his first 45 games, Ryan Ludwick has brought his average up to .239. The outfielder delivered a walk-off solo homer on Saturday, and is batting .319 with five homers and six doubles since June 14.
Ludwick was an All-Star in 2008 with the Cardinals, and never batted below .267 in three-plus seasons in St. Louis. He is a career .265 (13-for-49) hitter against current Cardinals pitchers.
Current Reds batters are hitting .257 against Westbrook. Joey Votto is just 1-for-9 lifetime against Westbrook, while Brandon Phillips is 7-for-17 with two doubles and a triple.