They touched down about half past noon local time Saturday, met with a 52-degree temperature and the telltale, raw air of October baseball. It was fresh and new for most of the Washington Nationals — the flight into the postseason, the bus ride past the Gateway Arch, the entrance into an empty stadium for a workout 22 teams won’t have.

“This team is always relaxed when it’s together,” Manager Davey Johnson said.

The St. Louis Cardinals had occupied the field earlier in the afternoon. Eleven pennants representing World Series titles flapped in the brisk wind, including the one they earned last season. Against the defending world champions, only four of the 25 Nationals on the playoff roster — starter Edwin Jackson, first baseman Adam LaRoche, right fielder Jayson Werth and reliever Michael Gonzalez — have ever played in the playoffs.

Most of the Nationals have never played in a postseason game. Most of the Cardinals won the World Series last year and have won all five elimination games they have faced over the past two postseasons, including Friday night’s victory over the Braves in the wild-card game.

“Playing in big moments year after year gives you an edge,” Cardinals Game 1 starter Adam Wainwright said. “I feel like you’ll be more comfortable in those situations when you’re faced with it over and over again. And last year’s experience — playing the last month of the season, like every day was your last — and going through that postseason where you’re the underdog every time, which we always are and which we are again, it gives you an edge. It gives you a sense of being comfortable in tight spots.”

Does experience matter?

“Not as much as you guys make it out to be,” Werth said to a pack of reporters.

“I don’t know if it doesn’t matter,” third baseman Ryan Zimmerman said. “I just think it’s overrated.”

“As much as people say it doesn’t,” Gonzalez said, “it does.”

Recent history shows teams have rarely reached their first postseason and crashed their way into October. Of the 17 World Series champions since the introduction of the wild card, 12 had gone to the playoffs at least one of the two seasons prior.

“It definitely helps,” Jackson said. “You have a lot people, once they go back multiple times they know how to handle different situations. But at the end of the day, it can be your first time and you can still go out and perform. It just depends on how you treat it.”

The majority of the Nationals cannot know how the enhanced pressure will affect them, because they’ve never felt it before. The spotlight probably would not affect an entire team, but rather take effect on an individual basis.

Explore the Nationals’ run to their first NL East title.

“There’s two types of guys,” Gonzalez said. “Either you’re going to back up, or you’re going to buck up. It’s one of those two. You’re either going to become a star, or you’re going to be scared of the situation. That’s just the truth. You’ll see that with individual players. Some guys can be playoff guys, and some guys can’t.”

Said Wainwright: “It depends on the man, to be honest with you. I think some people have it inside of them to step up and play great ball no matter what it is. And some people can get tight.”

The Nationals received a dose of near-playoff baseball down the stretch, playing 16 games, including three in St. Louis, against teams desperate to keep their playoff hopes alive. They feel those games provided an important test, but “I don’t think anything can totally prepare us for that situation,” reliever Ryan Mattheus said. “The playoffs are going to be a different beast altogether.”

The Nationals already know Sunday will carry a different kind of baseball than most of them have ever played. The new stress is unavoidable, but their reaction to it, they say, is what will matter.

“Playing in the playoffs, whether you have 20 years in the big leagues and five World Series rings or none, you’re going to turn your emotions up,” shortstop Ian Desmond said. “It’s about being able to control them and kind of deal with that.”

LaRoche lost in the only two division series he played in, in 2004 and 2005 with the Atlanta Braves, when he was in his mid-20s. He planned to give a simple message to his younger teammates: “Don’t think we need more out of you.”

“It’s before all the games start, making sure guys understand this isn’t the time to step up your game and go play harder,” LaRoche said. “We don’t say, ‘Now it’s playoff time. Now let’s get serious and make sure we’re all locked in.’ That’s not the way baseball works. You’ve got to be relaxed and comfortable. My biggest thing is, don’t change. It’s been good enough to get us here. It’s been good enough to win us a lot of series. Let’s not change something that’s proven to work.”

With Werth in the outfield, LaRoche in the infield, Gonzalez in the bullpen and Jackson in the rotation — and even Mark DeRosa, a veteran left off the roster, on the bench — every player, no matter the position, can seek counsel about what the playoffs have been like for them.

“Everybody has their veteran guys who have been there,” closer Drew Storen said. “It’s tough for me to go up to [DeRosa] and be like, ‘Hey, what’s it like in the playoffs?’ Because he’s a hitter. When you actually have guys that have played your position and have been there, it’s big.”

The Nationals possess a significant experience advantage in the dugout. Not counting the rings he earned as a player, Davey Johnson won the 1986 World Series and has managed 47 playoff games. Cardinals Manager Mike Matheny is a rookie skipper, and he gained all of his postseason managerial experience Friday night.

“I think we’ll be really good, because of Davey,” LaRoche said. “I don’t think he’ll let it get there. If he starts feeling some tension, he’s really good about coming in and cracking a joke or lightening the mood. He’ll say, ‘Hey, it’s a game.’ But I think we’ve got enough confidence now in what we’ve done all year. We’ll be able to stay composed.”

In either elation or despair, the playoffs test a player’s ability to stay composed. Every pitch could unravel 162 games of work. Every stolen base may help land you on a cereal box. Everyone is watching, and anything you do might be remembered.

“Man, it’s like a roller-coaster ride,” Gonzalez said. “Right when you’re on the top of it, and you’re about to go down, and you see everything — that’s the best way to explain that playoff run.”

The playoff run begins Sunday. It is time for fingernails to vanish and palms to start sweating. It is time for late afternoon shadows crawling across the diamond and the chill of early fall to be felt. It is time, in other words, to either back up or buck up.