The Capitals allowed four first-period goals in a 5-1 loss to the Blue Jackets in Columbus. (Paul Vernon/AP)

Goaltender Braden Holtby was the last Washington Capitals player out of the locker-room tunnel as the second period was about to start. His mask had been replaced with a baseball cap. Until a late empty-net goal, the scoreboard in front of him was frozen on the four goals he had allowed in the first period. The final score was a 5-1 Washington loss to the Columbus Blue Jackets, an outcome that was decided in the opening 20 minutes.

Holtby was yanked from the net early for the second time in his past four starts and the third time this month. Playing behind a team that has been plagued by inconsistency for the past two months, Holtby lost his sixth straight start, extending a career-worst personal stretch. With the loss and Philadelphia’s 1-0 shootout win over Montreal, the Flyers (78 points) have passed the Capitals (77) for first place in the Metropolitan Division.

With Philipp Grubauer in net, Washington couldn’t muster any more offense to supplement Alex Ovechkin’s power-play goal in the first period. The Capitals even had a three-minute power play to start the second. Grubauer made 18 saves, not allowing a goal, and it’s unclear which of the two goaltenders will get the start Tuesday night, when Washington hosts the Ottawa Senators at Capital One Arena.

“I’ve had [Holtby] for four years; I have a lot of confidence in Braden,” Coach Barry Trotz said. “He’s been a good goaltender for a long time. Yeah, I have confidence in him.”

Monday marked the Capitals’ first game on trade deadline day since 2014, and while there was speculation that Washington expressed interest in several marquee defensemen, the 3 p.m. deadline passed uneventfully. With the team allowing 3.20 goals per game in the 20 games entering Monday night’s, the Capitals addressed their defense when they traded for rental blue-liners Michal Kempny and Jakub Jerabek last week.

But General Manager Brian MacLellan admitted that the team explored acquiring a “higher-end” defenseman. The asking prices were ultimately deemed too high; Ottawa’s Erik Karlsson didn’t get dealt, and the New York Rangers traded Ryan McDonagh to the Tampa Bay Lightning.

While the Capitals played it conservatively, their rivals in the Eastern Conference got better. The Boston Bruins landed Rick Nash. Along with McDonagh, the Lightning added J.T. Miller. The Pittsburgh Penguins acquired Derick Brassard to center their third line, and the Toronto Maple Leafs traded for center Tomas Plekanec. The Blue Jackets made three moves, adding defenseman Ian Cole, winger Thomas Vanek and center Mark Letestu. Cole and Letestu were in the lineup Monday night.

“Obviously, they were energized by their day,” Trotz said. “They got a couple new people, and there’s always an excitement about that. They came with it in the first.”

Four hours after the trade deadline passed without the Capitals making any splashy moves, the team came out flat in Columbus, trailing 4-1 through 20 minutes after allowing the 30th-ranked Blue Jackets’ power play two goals on three man-advantage opportunities. After Artemi Panarin scored on a one-timer from the left faceoff circle just 5:31 into the game, Ovechkin countered with a nearly identical power-play goal less than two minutes later.

Ovechkin played the 984th game of his career Monday, passing Calle Johansson for the franchise record. His league-leading 39th goal of the season has him just three away from the 600th of his career.

Fifty-six seconds after Ovechkin’s goal, Columbus’s Sonny Milano beat Holtby five-hole with a spinning backhand in the slot. The third goal took an unlucky bounce: Matt Calvert’s pass from behind the net caromed off Nicklas Backstrom’s stick and to Letestu, who slammed the puck through Holtby’s legs as the goaltender attempted to slide over in time.

Capitals defenseman Brooks Orpik was called for interference three minutes later, and then Seth Jones scored on the power play with a screened point shot.

“Obviously, that wasn’t great of us,” Backstrom said of the first period. “We shot ourselves in the foot a little bit. Obviously, they were going from the start. It felt like they fed off their goal and obviously played better than us today.”

When the team returned from intermission, Grubauer was in the net and Holtby was on the bench in his baseball cap. Holtby entered Monday with a 14-3-2 record against Columbus, and he won his first three starts against the Blue Jackets this season, making more than 30 saves each time.

The Capitals’ trades for Kempny and Jerabek were intended to improve Washington’s struggles moving the puck up the ice and out of its end, but that continued to be an issue Monday night. The Capitals are 8-8-4 over their past 20 games.

“We’ve got to bail each other out,” Trotz said. “Sometimes the goalie is bailing you out. Other nights, you’ve got to bail the goalie out. It’s on everybody tonight, me included.”