Ottawa’s Zack Smith receives a face full of Mikhail Grabovski’s hand during a third period scuffle at Verizon Center on Tuesday night. (Alex Brandon/Associated Press)

The last thing the foundering Washington Capitals needed was to be without Alex Ovechkin, the league’s leading goal scorer and an omnipresent threat. The offense had produced more than one goal just once in the past five games — all losses — with him in the lineup. With Ovechkin sidelined Tuesday night by an undisclosed lower-body injury, that offense went from struggling to anemic.

Despite numerous chances and four power-play opportunities, Washington lost, 2-0, to the Ottawa Senators at Verizon Center, its 13th defeat in 17 games. It marked the first time since Nov. 25-Dec. 1, 2011, that the team had lost four straight games in regulation — and that span included the firing of Bruce Boudreau as coach.

Coupled with a win by the New Jersey Devils, the defeat knocked the Capitals back to sixth place in the Metropolitan Division and leaves them searching again for answers. They have been outscored, 19-7, during the six-game slide.

It was the third time this season the Capitals had been without Ovechkin, who suffered the injury against the New York Rangers on Sunday. The team won the two prior games without the star right wing, back in November when he was out with an injured right shoulder, but on this occasion missing Ovechkin was simply another blow to a wayward bunch.

“We missed Ovi a little bit tonight, more than I thought we would because we’ve handled it before,” Coach Adam Oates said. “We generated a lot of chances, other guys have got to finish. He can’t be the only guy.”

The Post Sports Live crew debates whether the Capitals' carrying three goalies on its roster contributed to the team's losing streak. (Post Sports Live/The Washington Post)

On a night when they needed to foster offense any way possible, the Capitals did not give Ottawa goaltender Craig Anderson much difficulty. Anderson finished with 34 saves in his third shutout of the season and saw every single shot that came his way. Washington, making the same mistake it did against Anderson in a 3-1 loss on Dec. 30 in Ottawa, never established any type of net-front presence to obstruct his view of the developing play or shot.

The Capitals had plenty of chances from the start and played a rather clean defensive game, which made the absence of a finishing touch offensively all the more frustrating.

“We’re working hard. Our effort was there tonight. We were doing the right things. We were getting pucks deep. We were getting shots to the net,” Troy Brouwer said. “Anderson made some good saves when they needed, but we got to score goals. We’re not scoring goals. I think we have two in our last three games — it’s not going to win you many games in this league.”

The teams got off to a scoreless start, as the first period held little traction for either squad, but for the Capitals playing 20 minutes without any costly errors and allowing themselves to establish a solid game could be considered a step in the right direction.

The best opportunity for the home team in the opening period was a rush by John Carlson, who maneuvered around Senators defenseman Patrick Wiercioch for a shot in close, but Anderson turned the puck aside. Anderson would do the same early in the second when Brooks Laich drove hard to the net for a chance and again when Eric Fehr fired a one-timer from point-blank range low in the right circle.

After all that momentum, the Capitals’ first significant mistake would wind up in the back of their net in the second period.

Jason Chimera and Mikhail Grabovski failed to win a battle for the puck down low behind the Senators’ net, allowing defenseman Eric Gryba to send a pass around the boards to Clarke MacArthur. Karl Alzner had pinched on the play, allowing MacArthur to spring Kyle Turris on a rush the other way. The lightning-quick Turris used rookie defenseman Connor Carrick as a screen and shot between Braden Holtby’s legs for a 1-0 Ottawa lead at 12:59.

“Turris made a nice play of faking the pass and hiding the puck from me and got a quick shot off between Connor’s legs before I could see his stick blade,” said Holtby, who finished with 24 saves in his first start since Jan. 4. “He just fooled me.”

The Capitals continued to have chances — including a pair of squandered man-advantages after Turris’s goal — but couldn’t solve Anderson.

Senators captain Jason Spezza added one more goal for insurance, a laser of a short-side shot on the power play for a 2-0 lead with 8:56 gone in the third that sealed Washington’s latest disappointment in this stretch of futility.

“When you win, it’s because you deserve to win generally. And if you’re not winning, do something extra,” Brooks Laich said. “Well done is better than well said. If you want to talk about it, go show it on the ice. Guys have tried it. The locker room, nobody’s yelling and screaming in here. We have to prove it to our teammates, prove it to yourself, the organization. We have to be better as players.”

Capitals notes: Defenseman Steve Oleksy cleared waivers and was assigned to the AHL’s Hershey Bears. . . . Rookie defenseman Nate Schmidt was recalled and played his first game since Dec. 13 on Tuesday night, skating 11:04 against the Senators.