James van Riemsdyk can’t put his finger on what exactly has caused the Flyers’ once-dangerous power play to fizzle.

“I don’t know, to be honest. It hasn’t looked good for most of the year," the veteran winger said Friday. “Even earlier in the year, I feel like we were getting some goals on kind of a more non-traditional-structure [for] power-play goals, like off the rush. That’s nice to get every once in a while, but it’s not necessarily sustainable."

It certainly hasn’t yielded results recently. The Flyers were 0-for-3 on the power play in Thursday’s loss to Arizona and are 4-for-33 in the last 11 games.

For years, the team’s power play was lethal. Last year, however, it ranked 22nd of 31 NHL teams.

Entering this season, new coach Alain Vigneault made some changes to the unit, and at first found success. In late October, the power play was thriving, ranking sixth in the league at 25.8%.

Observers credited the productivity to assistant Michel Therrien, who’s in charge of the unit, and players’ buying into the new coach’s aggressive system.

Both Vigneault and Therrien said at the time that they thought of the team as having two No. 1 power-play units, with the first group usually consisting of Claude Giroux, van Riemsdyk, Jake Voracek, Joel Farabee, and Shayne Gostisbehere; and the second often made up of Sean Couturier, Oskar Lindblom, Travis Konecny, Ivan Provorov, and Matt Niskanen.

In November, the Flyers’ fourth 10-win month in the last decade, the power play tied for 18th in the NHL, converting on only 16.7% of its opportunities. In the recent five-game win streak, which ended Thursday, the power play was 2-for-14.

At practice Friday, as the Flyers prepared to face the Ottawa Senators at 1 p.m. Saturday, Vigneault tinkered with a few different power-play units. But, the coach said, personnel might not be the crux of the problem.

“We tried this morning a couple different looks on some units there,” he said. “Obviously, execution is a big part of the power play. ... We’re not getting a lot of opportunities, but we’re getting two or three a game, so if you can make some of those count, it makes a big difference.”

Experienced players and newcomers have some ideas for how the power play could be revived.

“To be honest, I think just have a little simpler approach," van Riemsdyk said. “It sounds cliched, but shooting more pucks, recovering more pucks, just have a more aggressive mindset at the net. I think we’re maybe trying to make a perfect play too often."

Rookie Morgan Frost said his addition on power plays could be “messing with the chemistry a bit," but the 20-year-old doesn’t think the team should shake things up too drastically.

“I feel like in a season you’re going to have ups and downs,” he said. “I think maybe you can make little changes, but be confident in your ability and your structure, and I think things will turn around."

Breakaways

Vigneault said there’s “a good chance” the Flyers will return to playing six defensemen against Ottawa on Saturday after using all seven Thursday against the Coyotes. He said he has yet to decide which six. Forward Misha Vorobyev — who was once again recalled from the Phantoms this week, this time to replace injured Michael Raffl — might play on the fourth line. ... Young goaltender Carter Hart will start and get a chance to add another win to his impressive 7-1-2 home record.