The Washington Capitals entered Friday night’s home opener against the Buffalo Sabres missing four regulars, including captain Alex Ovechkin. Their night ended with a 4-3 shootout win — thanks to John Carlson — but the team may have suffered an even larger loss.

Forward Tom Wilson exited after taking only one shift in the third period and did not return after suffering a lower-body injury. The young winger has arguably been the Capitals’ best player during the first week of the season. He will be reevaluated Saturday.

The Capitals (3-0-2) came into Friday with their depth already being put to the test with four players on the covid-19 protocol-related absences list. An extended absence by Wilson, who already has three goals and three assists through five games, would create another hurdle.

“Sometimes, when you are faced with adversity, those are the sweetest wins and those are where you have to overcome some obstacles,” Coach Peter Laviolette said. “We felt good about the lineup. We certainly miss the guys that aren’t in there, but we felt good about the lineup. It was a really good win, really good hard-fought win for us.”

Friday’s win was Washington’s third shootout or overtime game — the previous two coming at Pittsburgh (a shootout loss and an overtime defeat). Carlson, who beat Buffalo goalie Linus Ullmark with a five-hole wrist shot, accounted for the lone goal in the shootout.

And while earning two points gave the Capitals a pinch of hope to start their six-game homestand, the attention remained on who wasn’t there.

Ovechkin, center Evgeny Kuznetsov, defenseman Dmitry Orlov and goaltender Ilya Samsonov were unavailable. The first three are in quarantine, and Samsonov is in isolation after he tested positive for the coronavirus Tuesday night. The four players will miss at least the next three games.

Through contact tracing, the team and league learned the four Russians hung out multiple times in a Pittsburgh hotel room during their four-game trip to open the season, according to one person with knowledge of the matter. At those gatherings, which violated NHL protocols, the players watched sports and played video games.

The four players cannot practice or play a game until they clear the protocol.

Friday was just Ovechkin’s 32nd missed game in a 16-year career that includes 1,156 appearances. The last time the Capitals did not have a Russian player dressed or in their lineup was Nov. 2, 2013, the last of two straight games Ovechkin missed with an upper body injury.

“Guys are going in and out,” Nicklas Backstrom said. “You just look at it, you’ve got to try and connect as a team and play as good as you can as a team. Even though I’m one of the leaders on the team, in this group I feel like everyone is stepping up and everyone is taking charge. . . . Everyone is valuable, and you need everyone to win a hockey game.”

With regulars out, center Brian Pinho, who made his NHL debut during the 2020 playoffs, played in his first career regular season game. Defenseman Jonas Siegenthaler made his season debut after being a healthy scratch for the first four games.

Capitals rookie goaltender Vitek Vanecek made his third NHL start and recorded 24 saves in addition to his first NHL shootout win.

“It was great to see,” Backstrom said about Vanecek’s performance. “I mean he’s really calm back there, and he really stepped up in the shootout. Especially when we missed a few there at the start. That was huge. That’s what gave us two points.”

Laviolette said he is not sure how many games Vanecek will get while Samsonov remains out but acknowledged the rookie had a chance to earn more time in the crease. Craig Anderson is the only other goaltender on the Capitals’ active roster.

“Whether [Vanecek] plays every other day or whether he gets the next start, I am just not there yet, so we are going to take everything in tonight and go from there,” Laviolette said. “But for a young goalie, if he gets half the starts, that is a chance to show what you can do. If you get more than that, that means things are going well.”

Eric Staal opened the scoring for Buffalo with 7:27 left in the first. Victor Olofsson stole the puck from Zdeno Chara behind the Capitals’ net and fed it to a streaking Staal, who beat Vanecek on Buffalo’s fourth shot on goal.

Backstrom tied things up at 1 with his third goal with 3:42 left in the first, a backhanded rebound that came off a deflection from Wilson following Brenden Dillon’s shot from the left point. Backstrom has five points in as many games, and Wilson leads the Capitals with six points (three goals, three assists) in the first five games, production that will be tough to make up if his absence becomes extended.

The middle frame again caused trouble for the Capitals as they struggled with defensive breakdowns and turnovers. Both teams lit the goal lamp twice in the second period thanks to miscues.

“The second period, that was the toughest period that we struggled with. . . . There is no question there are some things that we need to clean up defensively,” Laviolette said.

Nic Dowd gave the Capitals a 2-1 lead 4:14 into the period with his second goal, a snipe from the high slot off a feed from Jakub Vrana in the right circle. He had seven goals in 56 games last season.

Dylan Cozens, 19, scored his first NHL goal to tie it a 2 about six minutes later, stripping the puck from Pinho in the neutral zone and then moving in and snapping a shot from the right circle that went in off the crossbar.

Vrana put the Capitals up 3-2 with a rebound tally off Chara’s shot with 6:53 left in the second. Washington’s lead lasted all of 42 seconds before Riley Sheahan scored to knot the game after another Capitals defensive zone breakdown.