The Flyers have to pass an unfamiliar test after losing Game 4 to the Penguins.

There’s a lesson here for the Flyers, if they care to learn it.

Their 4-2 loss Saturday night in Game 4 of the Eastern Conference first-round series against the Penguins is not a cause for panic. Not yet. And it doesn’t have to be at all. They are still ahead three games to one. It will still take Sidney Crosby & Co. fashioning a minor moment of NHL history for the Penguins to win this series.

Again, calm is the appropriate word here.

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But the Flyers do face a test now. It was always a reach to think they would sweep this series, and now that they haven’t, they must regroup. They are a young team facing a reality that most of them haven’t confronted before.

No team goes unbeaten in the NHL playoffs, and Garnet Hathaway, whose 35 games of postseason experience make him close to a sage on this team, offered a reminder of that truth last week, after the Flyers had won Game 1.

“We’re not going to win them all,” he said. “How can we stick together when we lose one?”

The day had begun with news that suggested the Flyers might have to answer that question just yet. Goaltender Dan Vlǎdar, who had suffered an injury to his right arm in Game 3, participated in the team’s morning skate and was healthy enough to start. For a team that walked a high wire for weeks just to get into the playoffs, the announcement that their most valuable player was available should have been energizing.

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It wasn’t, and Vlǎdar himself didn’t help matters. He gave up a relatively soft goal to Sidney Crosby in the first period — a slap shot that Vlǎdar got his glove on but couldn’t stop — and committed a classic blunder in the second. Instead of letting a dump-in by the Penguins sail along the boards, Vlǎdar stopped the puck, stick handled it momentarily, and tried to flick it past Pittsburgh forward Rickard Rakell, who stole it from him and tucked it into the net.

It wasn’t a land war in Asia, but it was bad enough. The Flyers were now down two goals, and for the first time in this series, they had lost a key advantage to the Penguins. Vlǎdar had given them a clear edge in goal through the first three games.

But Penguins coach Dan Muse benched Stuart Skinner for Artūrs Šilovs in Game 4, and Šilovs was excellent, making 28 saves, fending off a partial breakaway by Tyson Foerster late in the second period, snatching a Travis Konecny wrist shot from the slot early in the third.

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But it took the Flyers too long just to generate those scoring chances, and coach Rick Tocchet hinted after the game that there might be lineup changes ahead for Game 5 on Monday. The players most conspicuous by their absences have been Foerster and Matvei Michkov, neither of whom has a point in the series. Foerster at least had that flash of promise Saturday night, but Michkov has been practically invisible.

“I thought some guys weren’t moving their feet,” Tocchet said. “It seemed like some guys were sluggish tonight. We’ll have to figure that out, get some energy there. ...

“I don’t know if it’s complacent. We didn’t do the little, small things: checking the body, winning some puck battles. I think they were a little more desperate at times. But like I said, we did fight back. That’s the good part of it."

Those little, small things, though, are often the determining factors in a postseason series. They can appear like nothing to the layman’s eyes. They can be everything when a team is trying to save its season, as the Penguins were Saturday.

The Flyers did not play terribly. They just didn’t play all that well, and at this time of year, that sort of effort won’t finish off an opponent with Pittsburgh’s pedigree. They didn’t get a stellar game from Vlǎdar, or from anyone else, and it cost them. It brought them back to reality. “Can’t get too frustrated,” center Christian Dvorak said. “We’re in a good spot. We’ll get back to work.”

They’ve lost one. Game 5 is Monday night back at PPG Paints Arena in Pittsburgh. Let’s see if they can pass this unfamiliar test.

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