Philipp Grubauer will be back as the Capitals’ starting goaltender in Game 2 against Columbus. (John McDonnell/The Washington Post)

The most disappointing moments in the Washington Capitals’ postseason-opening loss to the Columbus Blue Jackets might have also been the most encouraging.

As Coach Barry Trotz and his players reviewed where things went wrong Thursday night — with two costly penalties in the third period that squandered a pair of one-goal leads en route to a 4-3 overtime loss topping the list — the team was also fairly pleased with its overall play. Washington also knows it has “another level” that it’ll need to reach Sunday night to even the Eastern Conference quarterfinal series before it moves to Columbus for two games.

“We all know that,” Trotz said. “Individually, there’s a level of game that could be propped up or be better for a number of individuals in our room. And then if they do that, we’re collectively better, too. There’s some parts of our game that we’ve talked about we’re going to clean up and we’re going to be better.”

Mental lapses like Tom Wilson’s charging of Alexander Wennberg and Andre Burakovsky’s offensive-zone trip of Seth Jones — penalties that resulted in Columbus power-play goals that each tied the score — are infuriating considering the stage. “That’s Day One of training camp,” Trotz said. But that’s also easily corrected, so the Capitals didn’t overreact.

Trotz said he will stick with goaltender Philipp Grubauer on Sunday night after the German allowed four goals in the second playoff start of his career. Trotz said he doesn’t intend to make any significant line changes, either; a fourth-line forward might be pushed out because center Jay Beagle could return from his undisclosed upper-body injury.

Trotz was asked whether his team was relaxed Saturday. “I’d probably say we’re engaged, which is always a good sign,” he said.

“Yeah, I mean, it’s a typical playoff game — make a couple of mistakes, [and] the other team capitalizes and changes the game,” forward Devante Smith-Pelly said. “I think five-on-five, we played pretty well. We were creating chances, goalie made some saves, and we didn’t capitalize on a couple of chances. In the third, we have to kill those penalties; we have to bail those guys out late in the game. I’m not too worried about what happened in Game 1. We’re just moving on.”

Washington’s penalty kill will get a lift with the likely return of Beagle, who averaged the most shorthanded time on ice per game among the team’s forwards. But the Capitals have struggled with discipline all season — their 294 minor penalties were the seventh-most in the NHL — and Trotz was most frustrated by the poor situational awareness Thursday night, like Burakovsky chasing Jones behind Columbus’s net, a risky play when holding the lead and 5:05 left in regulation. Then on the penalty kill, Wilson had two chances to clear the puck before Jones eventually tied the game to force overtime.

“It’s a stupid play to make,” Burakovsky said. “If I could just go back and correct that, I would do it every day, but at the moment when it happened, I just thought I had a lot of speed behind him, and I thought I could catch him. Then he just had a good angle on the net and just took me out a bit. Yeah, that’s not the smartest play I’ve made in my career.”

Said center Nicklas Backstrom: “It’s just a learning thing for us, I think. We need to come out more prepared and make sure we play 60 minutes and not just 40. I think it’s just that. We gave the game away, and I think we should’ve had it. … It’s going to happen, so we just have to find a way to get through it.”

Backstrom said the Capitals played well for half of the game. Trotz described them as “average.” The teams were fairly even at even strength — Washington had 46 shot attempts to Columbus’s 51, though the Capitals had a slight edge in high-danger chances, according to Natural Stat Trick — and more five-on-five play is expected for the rest of the series with penalties typically called less often in the postseason.

Perhaps the best example of how quickly postseason fortunes can change is the other playoff series pitting Metropolitan Division foes. Pittsburgh beat Philadelphia, 7-0, in Game 1 on Wednesday, but then the Flyers rebounded with a 5-1 win over the Penguins on Friday, with their coach making no personnel changes in between. Trotz has occasionally been reactionary to playoff losses, scratching defensemen Dmitry Orlov and Nate Schmidt two years ago after games in which each had costly turnovers. There was some question of whether he’d change goaltenders and tab Braden Holtby as the starter for Game 2, but Trotz said he thought Grubauer was “fine” Thursday night. He expressed confidence in him to be better Sunday, as he did in his team.

“There was nothing in that game that you’d say, why didn’t you make a change?” Trotz said.

“Nobody’s walking through to the Stanley Cup with no losses,” Grubauer said. “You lose one and you learn from that and maybe guys realize, ‘Okay, we’ve got to do something different.’ … When you lose a game — you want to win the game — but you’ve got to learn from it and you’ve got to take some positives out. In order to be better, you need to see the negatives and you need to make mistakes and hopefully get better and learn from it.”

More Capitals coverage:

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The Capitals and Blue Jackets are already bloody. There could be more to come.