Capitals Coach Adam Oates walks toward the locker room as time ticks off the team’s 5-0 loss to the Dallas Stars. (Jonathan Newton/The Washington Post)

Two teams, each in a tight race to reach the postseason even if they reside in different conferences, met Tuesday night at Verizon Center — but only one played as though it wants to reach the playoffs.

Contemptible defense and the absence of desperation required to remain a relevant player in the Eastern Conference wild-card race resulted in a 5-0 embarrassment for the Washington Capitals against the Dallas Stars. As the goals piled up toward Washington’s fourth straight loss, each with less protest than those prior, it looked as though the team had accepted its fate.

“If somehow we make the playoffs and we play like this, who are we kidding?” Coach Adam Oates said he told the team during the second intermission, when they faced a three-goal deficit. “We have to figure out a way to get better. We have to stick together. It’s just us collectively in here. Obviously it’s very disappointing.”

Kari Lehtonen recorded a 35-save shutout and the Stars’ fourth line recorded three goals in the walloping that may have left Washington’s hopes of reaching the playoffs for a seventh consecutive season in ruins.

Washington sits with 81 points, two behind Columbus for the second wild-card spot in the East with six games to play, no tiebreakers and the Blue Jackets also have a game in hand. The Capitals were leap-frogged by wayward Toronto, which snapped an eight-game losing streak with a 3-2 win over Calgary to move to 82 points. And New Jersey — suddenly back in the chase — captured one point in a shootout loss to Buffalo and is just one behind the Capitals, who visit Newark on Friday.

The Post Sports Live crew tries to figure out the missing element from the Capitals that is preventing them from playing to their full potential this season. (Post Sports Live/The Washington Post)

Although the stakes of each game are clear with a simple glance at the standings, the Capitals didn’t play like a team aware of its position against Dallas, which is vying for the final wild-card spot in the West.

“There was zero urgency,” said Braden Holtby, who stopped 11 of the 13 shots he faced in a relief effort after starter Jaroslav Halak was pulled after allowing three goals on 23 shots in the first 29 minutes 50 seconds of the contest. But the tallies on this night shouldn’t be blamed solely on the goaltenders, as they were victims of Washington’s porous defense.

The Stars possess team speed that was evident from the outset and Washington clearly wasn’t able to match it, which meant the home team needed to rely on positioning and taking care of the puck. Rarely this season, though, has either or both of those elements been a consistent part of the Capitals’ game.

The problems created by Dallas’s quickness surfaced on the Capitals’ first power play when they gave up two shorthanded breakaways in a span of 32 seconds. First to Cody Eakin, a 2009 Washington draft pick who was traded to Dallas at the 2012 draft in the deal for Mike Ribeiro, and then Ryan Garbutt, who was slashed by John Carlson negating the remainder of the power play.

Then, just past the 15-minute mark, Washington spun out of control in its own zone. Presented with multiple chances to gain possession of the puck, win a battle or perhaps even clear the zone, the Capitals declined each one until finally Dallas put the puck in the back of the net.

Sure, Tyler Seguin had some luck as he battled along the boards when he tipped the puck toward Jamie Benn in the left circle and it landed right on the stick of the Stars’ captain. But Seguin and his linemates created it by sustaining possession and when he cut between Carlson and Karl Alzner a step ahead of Nicklas Backstrom to deflect the puck past Halak for a 1-0 lead it wasn’t fortune but a willingness to drive to the net.

“It can’t be justified, it’s terrible,” Alzner said of the lack of urgency. “We’re making bad pinches, we’re not covering for each other. We weren’t, haven’t been playing for one another. It’s like we expect the next guy to make the play. It’s been kind of off and on like that for a lot of the season and we’ve got away with it at times. It clearly hasn’t worked the last little bit and you pay for it in the end.”

In the second period, any semblance of defensive awareness vanished entirely.

A bad line change led to Alex Goligoski sending a crisp, stretch pass from the Stars’ defensive zone all the way to the offensive blue line where Ray Whitney and Alex Chiasson were posted behind Capitals defensemen Mike Green and John Erskine. The resulting two-on-zero culminated with Whitney pulling the puck around Halak and firing into an empty cage after the netminder went hard to his right to challenge the 41-year-old winger to put the Stars up 2-0 at 9:16 of the middle stanza.

“We played a fast game tonight. We had a lot of chances; we had a lot of two-on-ones, and we even had a 2-on-0,” Whitney said. “Not often do you see that many scoring chances.”

Thirty-four seconds later, Dallas made it 3-0.

The Stars immediately carried the puck into the offensive zone after the faceoff at center ice, worked it around to establish almost power-play like possession with Washington skaters collapsing around the slot and net. An initial shot from defenseman Trevor Daley at the point went off the left leg of Erskine and popped out into the right faceoff circle where Dustin Jeffrey fired the rebound back at Halak.

He made that save, but the puck was loose in his pads prompting three Capitals — Erskine and rookies Julien Brouillette and Chris Brown to all converge on Chiasson in front. While they managed to create a group bear hug on one member of the Stars’ roster, Jeffrey was unguarded right next to the pileup, found the puck and fired it high over Halak. That marked the end of Halak’s evening as Oates pulled the veteran netminder in his 10th start as a Capital. But that switch was of little consequence, as were the final 30 minutes of play for Washington.

Jeffrey added his second goal of the night midway through the third period and Garbutt finally got the shorthanded tally he was after, with just over five minutes remaining in regulation, to level one final blow.

“It’s hard to say something right now because we’re in desperate position,” said Ovechkin, who hasn’t scored an even strength goal in 16 games. “We understand we need the points, but we don’t get the points, and we make easiest mistakes. We turn puck over in our zone, neutral zone, and cost us the game, you know? It’s all about us. It’s all about players. We didn’t respond, and I don’t know what to say.”

Capitals notes: Dustin Penner sat out Tuesday’s game with an illness. . . . Jack Hillen missed a third consecutive game with an undisclosed upper-body injury he sustained during a violent collision with Alex Ovechkin on March 25 against Los Angeles.