If the Flyers are going to make the playoffs this season, they must make dramatic improvements on their special teams.

Through four preseason games, the jury is still out.

While the power play has made strides, the penalty kill has struggled. Granted, there has been a lot of experimentation, and the primary special-team units won’t play together until Friday’s preseason finale against Washington.

The addition of veteran defenseman Keith Yandle has bolstered the power play. Yandle has been the quarterback on the first unit and has shown a great knack for getting pucks through to the net or finding an open man. The Flyers moved the puck well and had good power-play chances against the Islanders in their first preseason game but went 0-for-3.

Since then, they are 4-for-14 (28.6%) heading into Tuesday’s exhibition against the Islanders. (For context, the Edmonton Oilers led the NHL in power-play success rate last season at 27.6%.)

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Yandle, who captain Claude Giroux says has livened the locker room like Kevin Hayes did when he arrived two years ago, said he has used training camp to learn the “little things, like where guys like the puck when they’re shooting a one-timer — and whether it’s on their back foot or their front foot. And where guys like to come down the flanks when they’re coming into the zone. There’s a lot of little things — where guys like it when they tip the puck. I’ve been working with JVR [James van Riemsdyk] and the net-front guys. It’s been good to have the time to work on things like that and get familiar.”

Yandle has a pass-first mentality, although he says he wants to alter that a bit.

“This year, I’m going to try to shoot a little more than normal,” he said after practice Tuesday in Voorhees, saying players like Giroux and Sean Couturier “are so good at making passes; they’re pass-first guys as well, and I think to open everything up, I’m going to have to shoot the puck as well.”

The power play is starting to click and “creating momentum even if we’re not scoring … and it’s carrying over into our five-on-five play,” Couturier said after scoring a power-play goal in the Flyers’ 2-1 overtime win Monday over Boston.

Conversely, the penalty kill had allowed at least one goal in each of the first four games. The unit was just 8-for-13 (61.5%) entering Tuesday.

“There are a lot of players who have played on the PK in the preseason,” Giroux said. “It’s a [work in] progress. We have new guys, and knowing what your teammate on the ice is going to do [is key]. I think you’ll act a little faster when you get to know them a little bit more.”

Last season, the Flyers finished next-to-last in the NHL (30th) with a 73.1% success rate on the penalty kill. They were tied for 18th in the league on the power play, 19.2%.

Flyers trim roster to 42

The Flyers reduced the roster from 51 players to 42 ahead of the club’s final two preseason games.

Goalie Samuel Ersson; defensemen Logan Day, Mason Millman, and Wyatte Wylie; and forwards Samu Tuomaala, Maksim Sushko, Max Willman, and Matthew Strome have been sent to the AHL Lehigh Valley Phantoms. Winger Elliot Desnoyers, 19, was the ninth player to go, and will return to Halifax of the Quebec Major Junior Hockey League.

The Flyers have more cuts to make as they must trim the roster to 23 before the Oct. 15 season opener against Vancouver.

Frost update

Rookie Morgan Frost, battling for a middle-six center spot, has no points in three preseason games, but he is making other contributions. In Monday’s win over Boston, for instance, he had four hits and won 60% (6 of 10) of his faceoffs.

“I feel like a bit more of a complete player,” Frost said. “I don’t feel uncomfortable in the D zone anymore. ... I’m just trying to concentrate on the details. Maybe I’ve sacrificed some offense so far, but I think those little things are important. Keep doing those and hopefully the offense will come.”

Breakaways

The Flyers took their junior varsity team to Bridgeport, Conn., for their game Tuesday against the Islanders. Only 10 players expected to make the opening-night roster made the trip: Derick Brassard, Scott Laughton, Nate Thompson, Nic Aube-Kubel, Connor Bunnaman, Travis Sanheim, Justin Braun, Rasmus Ristolainen, Martin Jones, and the winner of the No. 7 defenseman battle between Nick Seeler and Adam Clendening. … Giroux said Friday’s exhibition against the Capitals is important because both teams are expected to use their regular lineups, and you “get the feel of the pace of the game. You can practice as much as you want, but when you get in the game, it’s totally different. I think Friday will be a big game for us to be able to play against a full team, and especially for us to have our full lineup.” ... On Tuesday, Flyers Charities announced its three main initiatives for the upcoming season: supporting families impacted by cancer, growing the game of hockey in diverse communities, and championing environmental sustainability. As part of the commitment to the new priorities and its multiyear partnership with the American Cancer Society, Flyers Charities has committed to donating $75,000 to the ACS’s HEALED (Health and Energy Through Active Living Every Day) initiative.