The Cardinals look for a third straight victory while trying to hand the Pirates a season-high fifth consecutive defeat Wednesday night at Busch Stadium.
St. Louis (68-50) dropped four of five at Pittsburgh from July 29-Aug. 1 to fall out of first place. It then lost six of 10 before moving within two games of the Pirates (70-48) after overcoming an early 3-0 deficit to beat Pittsburgh 4-3 in 14 innings Tuesday.
"We had a lot of guys step up,'' St. Louis manager Mike Matheny said. "That was a big, big win. It was one of those ones you just felt you had to win somehow.''
The Pirates have totaled 10 runs during a four-game skid that followed a five-game stretch in which they averaged 4.6. They've also dropped five straight and seven of eight on the road.
St. Louis' Jon Jay, who scored the winning run on Adron Chambers' single Tuesday, had four hits and Matt Carpenter added three. Daniel Descalso scored the tying run in the ninth after he reached second base on a dropped fly ball by Pittsburgh left fielder Starling Marte.
"We got nicked for a run. We had to play five more after that,'' Pirates manager Clint Hurdle said. "We threw everything out there, they threw everything out there.
"We let one probably get away from us.''
Jay is 10 for 22 in his last five games versus Pittsburgh, while Carpenter is 8 for 15 with four doubles in the last three overall.
St. Louis' Shelby Miller (11-7, 2.89 ERA) will make this start after he was struck on the right elbow with a ball on his second pitch of last Wednesday's 13-4 loss to the Los Angeles Dodgers.
"To stay out there for 100 pitches (Wednesday) night, my arm would probably feel worse than it does," Miller told the Cardinals' official website the day after the injury. "That's something to be happy about. I got lucky there."
The Cardinals have been outscored 14-0 while Miller's gone 0-2 with a 3.86 ERA against the Pirates this season. The right-hander gave up two of his three runs on solo homers while striking out seven in 5 2-3 innings of a 9-0 home loss to Pittsburgh on April 28.
He'll be opposed by Francisco Liriano (12-5, 2.83), who improved to 2-0 with a 1.93 ERA against the Cardinals when he gave up a run, four hits and fanned eight in seven innings of a 9-2 victory July 29.
The left-hander allowed one run and struck out 22 over 21 2-3 innings during a three-start winning streak that ended Friday when he was roughed up for 10 runs and 12 hits in 2 1-3 frames of a 10-1 loss at Colorado.
"This is the big leagues, and every once in a while you have those kind of nights, unfortunately," Hurdle told the Pirates official website. "Nobody likes it; he doesn't like it. You don't psychoanalyze it, you don't overcook it."
Pittsburgh's Andrew McCutchen hit a two-run homer Tuesday, and is 16 for 32 with nine RBIs in the last 10 games.
Teammate Pedro Alvarez, however, is batting .182 in his last 25 games and is 3 for 20 with six strikeouts in the last five versus St. Louis.