The St. Louis Cardinals know they're heading to the playoffs for a fourth straight season, but in what capacity still remains in doubt.
After having their NL Central lead trimmed by a game, the Cardinals look to bounce back against surging Chicago Cubs starter Jake Arrieta on Wednesday night at Wrigley Field.
St. Louis (88-70) holds a 1 1/2-game advantage in the division over Pittsburgh, which beat Atlanta to clinch a playoff berth Tuesday before the Cardinals fell 4-3 in 10 innings to the Cubs.
The Pirates have five games remaining while St. Louis finishes its season with three at Arizona after this finale. The Cardinals' magic number is four to win their second straight Central title and avoid the do-or-die wild-card game.
"Obviously, Pittsburgh is playing well right now," said Shelby Miller, who didn't make it out of the fifth inning Tuesday. "No doubt, that team is not going to give up. But then again, neither are we. We know what we're capable of and will take it day by day and try to win each game."
St. Louis likely will be in for a tough test against Arrieta (9-5, 2.65 ERA), who is 1-0 with a 1.21 ERA in four career starts against the Cardinals, including three this season.
Arrieta had a no-hitter with one out in the eighth inning before it was broken up by Brandon Phillips' double in last Tuesday's 7-0 win over Cincinnati. It was the only hit he allowed while striking out a career-best 13 in the first complete game of his five-year career.
''It was nice to finally shake the catcher's hand at the end of the game,'' Arrieta said. ''That's something I've wanted to do my entire career.''
The right-hander added another solid moment during a breakout season three years after having elbow surgery. The Cubs took a risk in a July 2013 trade with Baltimore to acquire Arrieta, who is hoping to be a mainstay in the rotation for years to come.
"I've overcome a lot of things in my career, started to establish myself, put myself in a position like this," Arrieta told MLB's official website. "That's kind of the territory I'm in. I welcome it."
Arrieta allowed two runs in six innings before the Cubs' bullpen fell apart in a 6-3 loss July 26 the last time he faced St. Louis, which counters with John Lackey as he looks to boost his resume for the Cardinals' postseason rotation.
Lackey (3-2, 4.50) is coming off his longest outing since being acquired from Boston at the trade deadline after he allowed one run in 7 2-3 innings of a 2-1 win over Cincinnati on Friday.
The right-hander went nine days between starts after being pushed back in the rotation, a move he was not happy about.
''Yeah, I guess it helped. We'll go with that," Lackey said. ''I definitely felt better than I have in a couple weeks, for sure.''
Lackey had a shaky outing against the Cubs on Aug. 31, giving up five runs - two earned, all in the second inning - in 6 1-3 innings of the Cardinals' 9-6 victory.
Chicago (70-88) had lost four of five before Welington Castillo drove in Anthony Rizzo with a walk-off single Tuesday. Castillo also hit a two-run homer as the Cubs improved to 4-4 against the Cardinals at home this season.
Starlin Castro has been out since injuring his ankle Sept. 2, and manager Rick Renteria said the shortstop will be held out for the Cubs' final four games.