Jayson Werth (0 for 4) and the Nationals are finding offense hard to come by against the Cardinals. (Alex Brandon/Associated Press)

Patience collided with urgency Tuesday night somewhere between Davey Johnson’s office and the Washington Nationals’ clubhouse, which houses a team unfamiliar with losing and, maybe, conflicted about how it should respond. After a 2-0 loss to the St. Louis Cardinals at Nationals Park, players vowed time would reveal their ability. Down the hall, Johnson studied a lineup that had produced two runs in 28 innings and planned changes for Wednesday afternoon.

“I’m usually pretty patient, but I’m getting to my rope’s end,” Johnson said. “The effort is there. We’re just not getting it done. We’ve got the players who can get it done. We’re just not getting it done. It’s time to get a little mad.”

The joyride of last year sputtered to a final stop Tuesday night as Adam Wainwright crammed 81 / 3 innings of nine-strikeout, five-hit mastery down the Nationals’ throats. Their offense stranded Ross Detwiler, who deserved better after allowing two runs in six innings.

Last year’s Nationals knew only the freedom of winning. These Nationals now know the stress of losing. They dropped to 10-10, the first time they have been .500 or worse since April 9, 2012. World Series favorites on opening day, the Nationals are 1-7 against opponents with winning records. The Nationals have lost eight of their past 11 games, which did not happen once in 2012.

“Rock bottom, it feels like,” first baseman Adam LaRoche said.

The Post Sports Live crew discusses whether manager Davey Johnson bears the responsibility for the Nationals’ slow start to the season. (Post Sports Live)

It may still be April. But the Nationals last year did not ever deal with such a sustained stretch of failure. So what happens now?

“I don’t know,” Detwiler said. “I’ve never really been in this situation before. This is Game 20? Of 162? So I think it’s early.”

Johnson thinks it is time for change. He promised Wednesday’s lineup would be missing some regulars. LaRoche, especially against Cardinals left-hander Jaime Garcia, may be a prime candidate. He struck out in each of his four at-bats Tuesday, leaving him 0 for his past 10 with seven strikeouts. The most damaging came when he could not check his swing on Wainwright’s eye-high, 2-2 fastball with the bases loaded and two outs in the sixth inning.

“Needless to say, he had my number tonight,” LaRoche said. “Punched out four times and left 100 guys on base. Bad timing. All of it.”

Nationals players insisted 20 games should not cause their anger to boil over. They may have a collective .301 on-base percentage. They have scored two runs or fewer in seven of 10 games. They believe following Johnson’s directive — “get mad” — may only drive them deeper into quicksand.

“I understand why it’d be so frustrating for us and it would be easy to turn that way and just be [ticked] off about everything,” second baseman Danny Espinosa said. “But what’s that going to do? It’s going to put added pressure on every single guy in the clubhouse, trying to do more, trying to get outside of their game. You’re putting too much pressure on every single guy.”

Said LaRoche: “The whole team is frustrated. What do you do? Are you going to try harder? Swing harder? It doesn’t work. We’ve got to stick with our plan and expect it to work eventually.”

Their plan may already have been interrupted by their reaction to the sky-scraping outside expectations. In the past, Washington may have celebrated a team that reached .500 after 20 games. Now, it will not tolerate it.

“Maybe from everybody picking us as a candidate to win our division, everybody’s trying to be a little better than they need to be instead of just relaxing, going out there and doing what you’re capable of doing,” Johnson said before the game. “I don’t really worry about it because I know the talent that’s there. I know water seeks its level. We’ll be fine. Just need to get going.”

Prior to their latest loss, standing by the batting cage, General Manager Mike Rizzo refused to consider the notion forwarded by Johnson: That preseason attention — the hype of being favored to win the World Series — had anything to do with an uneven first month.

“I don’t buy that at all,” Rizzo said. “I think those are all external. It’s not internal whatsoever. There’s guys that are possibly trying too hard. I could see that. As far as a result of external messages, I don’t believe that.”

If the first 20 games have left you wondering what happened to the swashbuckling bunch that won 98 games last year, Rizzo offered a message: Wait.

“I like the team we have,” Rizzo said. “I think we’ve got a good ballclub, and we’re going to win a lot of games this year. It’s early. I’m a big proponent of, ‘It’s a long season.’

“I think people that are fans of the team, they go game by game. If these players went game by game and lamented over each loss and celebrated over each victory, you couldn’t survive in a season. You really have to take a broad view and look at the big picture and really play the game inning by inning, at-bat by at-bat, but you have to have a broad view of it. Otherwise, the grind of the season will just chew you up.”

The slog of losing eight of 11 may be chewing them up now. Nationals hitters showed anxiousness all night against Wainwright. His looping curve and mid-90s fastball may have overpowered the most securely disciplined offense. But 23 times, the Nationals swung at the first or second pitch of an at-bat.

Wainwright retired 15 of the first 16 batters he faced, including 13 in a row heading into the sixth inning. Singles from Kurt Suzuki and Denard Span finally broke the spell. Typically impatient, Jayson Werth popped the first pitch he saw a few feet behind second base.

Wainwright walked Bryce Harper on five pitches — the first walk he had allowed all season, after 342 / 3 innings without one free pass. The inning fell, with the bases loaded, to LaRoche. Wainwright set a trap for a hitter trying to make up for three tough weeks, a 2-2, 94-mph fastball at LaRoche’s neck. LaRoche could not check his swing.

In the seventh, after the Nationals had finally found a sliver of vulnerability in Wainwright, they responded with a whimper. Three batters saw five pitches.

“Some guys might need to get a fire lit under them to get it going a little bit,” Suzuki said. “We’ve just got to stay with the process, not panic too much and not read too much into how things are going. We’ve got to stay even-keel and keep going.”

Afterward, LaRoche searched for perspective. Tuesday afternoon, 11 Nationals players, along with other team personnel, rode a bus to Walter Reed Hospital and visited with wounded veterans. After that, getting mad did not seem necessary.

“Our problems are pretty minuscule compared to what some of those guys are going through,” LaRoche said. “It is a game. I don’t think it’s time for drastic changes in here. For guys to lose control. Again, you ride it out. That’s why you play 162 of them.”