ST. LOUIS -- Now the real work begins.

The Cardinals fell to the Cubs in a 3-2 rain-stunted affair at Busch Stadium on Sunday afternoon, ending their regular season with a 90-72 record but at least leaving the field with one key nugget known: they are heading to Los Angeles to play the Dodgers in Wednesday’s National League Wild Card Game.

• Box score

That was up in the air as of first pitch on Sunday, with the Giants and Dodgers still battling it out for the NL West crown. But with San Francisco coming away victorious, the Cardinals’ fate was sealed. They will make a trip to L.A. for a showdown between Max Scherzer and Adam Wainwright.

“If we're going to go to where we want to go, we’d like to go to the team that won it the previous year,” said manager Mike Shildt. “We might as well start with it right off the bat.”

“We're ready to go,” said starter Jake Woodford, who went five strong innings in the loss. “The whole roster is excited for this opportunity. … Everybody's ready to show up and do their job, get after it. We're excited to go out there and play.”

There were two important developments the Cardinals witnessed on Sunday before they can start their postseason run:

Flaherty on the come-up

Most notable about the Cardinals’ performance on the field on Sunday -- which was called after seven innings and after the organization honored the career of Mike Shannon -- was that Jack Flaherty threw a scoreless sixth inning as he continues to test himself for the postseason. It was not a back-to-back appearance, but it was as close as he could have made it, warming up in the bullpen on Saturday night for a 10th inning that never came.

Results-wise, it was close to ideal as the Cardinals could have hoped; Flaherty needed 18 pitches for a perfect frame with two strikeouts. His slider collected four whiffs on the eight times he threw it -- a wholly positive sign -- and his fastball topped out at 95.1 mph as he works back from a month-long absence due to a right shoulder strain.

Shildt said that the plan is indeed for the Cardinals to carry Flaherty on the Wild Card roster and have him available out of the bullpen. What will be interesting is the conversation that follows, whether they want to test Flaherty’s health for a potential NL Division Series by having him pitch on back-to-back days or if he’s forced to watch from the dugout.

Flaherty has not pitched more than one inning, maxing out at 19 pitches, in three outings since his return from the injured list.

Carpenter’s near magic

The moment was there for the taking. Matt Carpenter, with his Cardinals facing a one-run deficit, had two runners on base and a chance to play out his potentially final game at Busch Stadium as the hero.

Instead, what unfolded was a brutal microcosm of his season.

Carpenter lined what seemed to be a go-ahead double just foul, and then -- as brutal luck would have it -- flied out on the next pitch. That ultimately resembled the last at-bat of the rain-shortened affair.

That ended Carpenter’s 11th, and perhaps final, Cardinals regular season with a .169 batting average and a .581 OPS -- struggles he has been public in acknowledging and attempting to fix. He has a vesting option for 2022 based on plate appearances that he did not attain this season, yanked from a starting role and turned into a bench bat.

But if Carpenter’s struggles -- mental, physical and mechanical -- this year result in production come the postseason instead, he will surely take that in stride.

"I would gladly have a season where you didn't do what you felt like you could from a production standpoint -- I would go through that again to get a couple big hits to change a game in the playoffs and help us advance,” Carpenter said. “Those are the ones that really matter and the ones you want to come through for."

If Carpenter does not get one more at-bat at Busch in the NLDS, he’ll cherish the extra time he spent pregame alone on the field and the family pictures he took postgame, Gateway Arch in the frame.