They got the job done in Cincinnati, taking two of three from the Reds this past weekend and kicked off the second series the right way, winning the opener against the Pirates, 5-4, but dropping the second game, 9-0.
While he certainly is hoping to take the series from the division-rival Pirates, Cardinals manager Mike Matheny said the three-game stint is as important as all the others.
"Every series is important. Every game is important from here on out," Matheny said. "It's an exciting [series], obviously, because there is energy in all these stadiums. The excitement of late-season baseball is always there, but we're not falling into the trap of trying to put any more attention or focus on one particular game or series. Just play the game each night."
The Cardinals sit two games ahead of the Pirates in the standings and are clinging to the second Wild Card spot in the National League.
St. Louis will send rookie righty Joe Kelly to the mound Wednesday for his 13th start of the season after being moved out of the rotation
Kelly (4-5, 3.26 ERA) made the first start of his career June 10 and holds a 3-5 record with a 3.75 ERA in 12 starts this season.
He'll face an eight-year veteran as Wandy Rodriguez takes the mound for the Pirates.
Rodriguez is 7-11 with a 3.73 ERA lifetime against St. Louis but has recorded just one win since making the move to Pittsburgh last month.
He is 1-4 with a 4.86 ERA through six appearances (five starts) with the black and gold and is coming off a loss Friday despite putting up solid numbers.
Rodriguez (8-13, 4.01 ERA in 2012) pitched 6 2/3 innings, allowing three runs on six hits against the Brewers.
"He looked great," said Pirates catcher Rod Barajas. "Our conversation in the dugout was all positive. He didn't seem like he was too worried or putting extra pressure on himself. He was just out there pitching. He did a great job. Unfortunately, we weren't able to do enough to get him a win."
Cardinals: Lynn working way back to rotation in bullpen
While Kelly's spot in the rotation isn't a completely new one, the man he replaced is adjusting to his new role as a reliever.
Kelly took over for Lance Lynn, who has made 25 starts this season. Lynn faced a streak of struggles in August that forced him to the bullpen, where he made his first relief appearance Monday.
Lynn tossed 1 1/3 innings in the 4-3 win against the Pirates, allowing one unearned run on two hits.
"I want him to keep his mind prepared and his extra work going in that direction of possibly being a starter again," Matheny said. "We don't know how or when. And right now, we want him to take a lot of pride in helping us from the bullpen."
Catcher Yadier Molina left Tuesday's game in the second inning after a nasty collision at home plate with Pirates infielder Josh Harrison.
The club announced he was diagnosed with a left upper back, neck and shoulder strain, and he is day to day.
The Cardinals were down, 1-0, in the second frame, when Harrison tried to score from second on a two-out single. Harrison bowled into Molina as the catcher fielded the throw from right fielder Carlos Beltran.
Harrison's left elbow hit Molina in the head and knocked him to the ground, but he was called out as Molina held on to the ball.
Molina eventually stood up, before collapsing back onto his knees and being helped off the field.
Pirates: Club releases Bedard, calls up d'Arnaud
The Pirates on Tuesday unconditionally released left-handed pitcher Erik Bedard and recalled infielder Chase d'Arnaud from Triple-A Indianapolis.
d'Arnaud fills a void left by Neil Walker, who continued receiving treatments for lower back tightness that kept him out of Monday night's game.
"Chase is here to give us the flexibility to do more things with our other infielders," said manager Clint Hurdle. "[Walker] felt a little better but needed to be seen by another doctor. He'll be in the clubhouse later, and we'll see where we're at."
d'Arnaud may be in the big leagues only briefly, but he could earn one of the spots on the expanded September rosters.
Pittsburgh's Jason Grilli made his 52nd appearance of the season Monday night. He has been scored upon just once in his past 15 outings.
St. Louis' Matt Holliday is just one hit shy of career knock No. 1,500, and Molina is four hits away from No. 1,000.