Baseball's best record and a comfortable NL Central lead give the St. Louis Cardinals the luxury of skipping their most consistent starter in preparation for the postseason.
The surging Chicago Cubs weren't intimidated in the series opener and now face Michael Wacha on 10 days' rest as they seek a fifth straight win Tuesday night in St. Louis.
Wacha (15-4, 2.69 ERA) was scratched Wednesday against Washington to limit his innings over the regular season's final month. He's thrown 50 1/3 more than in 2014, when he missed nearly three months with a stress reaction in his right shoulder.
The right-hander is 4-0 with a 0.92 ERA in his last six starts but hasn't pitched since allowing four unearned runs in six innings of a 5-4 loss Aug. 28 at San Francisco.
The Cardinals (87-50) lead the Central by 5 1/2 games over Pittsburgh and will reach the playoffs for a fifth consecutive year barring an epic collapse. A priority for manager Mike Matheny is to have Wacha fresh for October.
"There are reasons we need to take a little pause whenever we get an opportunity," Matheny told MLB's official website. "I explained that to him as well, because he's not overly excited about it."
Wacha beat the Cubs on June 27, but he allowed five runs in six innings against them July 8 before the Cardinals rallied for a 6-5 win. Starlin Castro (8 for 17 with a homer and two doubles) and Anthony Rizzo (7 for 17 with a home run) have hit Wacha well throughout their careers.
Castro had two hits and Rizzo drove in a run Monday as the Cubs (79-57) dealt the Cardinals a fourth defeat in five games with a 9-0 victory. Dexter Fowler led off the game with a homer and added a two-run double, and rookie Addison Russell hit a three-run shot.
Chicago pulled within two games of the wild card-leading Pirates and increased its edge to 8 1/2 over Washington for the NL's last playoff spot. The Cubs also won for just the second time in their last 10 at Busch Stadium.
"We've got to beat them here. That's really important regarding our development," said manager Joe Maddon, whose club has outscored opponents 31-9 during a four-game win streak. "It's a nice first step, but let's have another one-game winning streak tomorrow."
The Cubs extending their run could hinge on Jason Hammel (7-6, 3.55 ERA) ending his slump. The right-hander has gone 1-1 with a 6.52 ERA over his last four outings and gave up a run in the first inning for the third time in five starts during the Cubs' 7-4 loss to Cincinnati on Wednesday.
"The real thing I want to get out of is the first inning," Hammel said. "I have to set a better tone to the game."
Hammel opposed Wacha on July 8 but left after the first inning with a hamstring injury. He allowed four runs in four-plus innings of a 4-1 loss June 28 in St. Louis and has struggled against Jason Heyward (9 for 16), Yadier Molina (5 for 11 with three doubles) and Jhonny Peralta (9 for 23 with two homers and two doubles) in his career.
Heyward went 0 for 10 over his previous three and Molina 0 for 13 in his previous four before both went 2 for 2 on Monday. Second baseman Kolten Wong wasn't in the starting lineup because of calf tightness and it's unclear if he'll start this contest.
Maddon said rookie Kyle Schwarber, who has missed the last five with rib and oblique issues, could return at some point this series.