Neil Greenberg, The Post's stats guru, breaks down the Washington Captials' offseason roster moves and whether the team has enough to seriously contend for the Stanley Cup. (Thomas Johnson/The Washington Post)

On Monday night, Alex Ovechkin accidentally set his alarm for 8:30 p.m. instead of 8:30 a.m. He overslept Tuesday morning, arriving at Kettler Capitals Iceplex too late to participate in the morning skate. It was then that Coach Barry Trotz informed his team captain that he wouldn’t play that night.

Ovechkin arrived at Verizon Center about an hour before the puck dropped, not unusual for players who have been scratched. The Washington Capitals, who had earlier called Ovechkin “a game-time decision,” announced that “personal reasons” had sidelined their star. That led to a flurry of speculation about an undisclosed injury or family emergency, but when Ovechkin returned to practice Wednesday, those reasons were revealed as disciplinary.

“I make mistake, so that’s why,” Ovechkin said.

With the Capitals coming off their worst loss under Trotz — a 5-0 thrashing by the San Jose Sharks — Ovechkin will be back in the lineup Thursday. The Capitals admitted they could have used the prolific goal scorer Tuesday night, though they maintained his absence was no excuse for the uninspiring performance.

It was just the 27th game Ovechkin has missed in his 11-year NHL career and only the fifth time both he and linemate Nicklas Backstrom, recovering from May hip surgery, have sat out of the same game, according to the Elias Sports Bureau.

“It doesn’t happen too often,” Backstrom said. “. . . He wants to be out there, and he doesn’t like to miss games. He’s a big part of this team, and he’s so important.”

Ovechkin watched the game with Backstrom at Verizon Center, describing the experience of watching San Jose shell the Capitals as “it was suck.” Backstrom said he and Ovechkin were mostly quiet; at intermission, the silence was broken with chit-chat about how funny Comcast SportsNet announcers Joe Beninati and Craig Laughlin were.

Trotz said he disciplined Ovechkin — who has 476 career goals — because “it’s an accountability factor that we’ve put in with our team rules” and that he believed Ovechkin made “an honest mistake.” Trotz said the Capitals were vague about Ovechkin’s status Tuesday because they didn’t want the game-day distraction of Ovechkin as a healthy scratch being disciplined.

“Everybody’s accountable in our room, and I think that’s good leadership,” Trotz said. “Everybody messes up. That’s just the way it goes.”

Said Ovechkin: “It’s the team rules. We talked and have a conversation, and I think we understand each other.”

A reporter asked Ovechkin, “What time did you actually wake up?”

Neil Greenberg, The Post's stats guru, breaks down the NHL's contenders and looks at the most intriguing story lines of the 2015-2016 season. (Thomas Johnson/The Washington Post)

“Maybe you want to ask what time I go to bed,” he said with a smile.

Perhaps the comment was made in jest, but Ovechkin has a reputation for a hard-partying past. He was once photographed partying with Russian club dancers on a yacht in Turkey. He turned 30 in September, and he got engaged this summer. He said he has missed team meetings before because of traffic but never a morning skate.

Trotz called the loss “a wake-up call” before Washington faces the Stanley Cup champion Chicago Blackhawks on Thursday. After a 30-minute practice Wednesday, Ovechkin led the stretch at center ice. The players huddled and then left the ice at the same time, a departure from the normal routine in which players trickle off after shooting pucks.

“Everybody coming off together,” Trotz said. “If we’re going to have any success, it’s going to be together. We need each other, we need to rely on each other and we need to play the game as a group better than we have. That was sort of the reason.”

Backstrom said the Blackhawks are a challenge the Capitals should look forward to. Though he has been cleared for contact, he’s unlikely to play against Chicago. But Ovechkin will be back in the lineup, an opportunity for the Capitals to put two embarrassing episodes behind them.

“We played a bad game,” Ovechkin said. “I hope [Thursday] is going to be a different game for us.”