Goalie Carter Hart is sidelined by apparent back spasms, but he is expected to play when the Flyers’ season resumes Aug. 2 against Boston.

Still, back injuries can be unpredictable, so there is a chance backup goaltender Brian Elliott could have a more important role than expected in the postseason. The Flyers and their coaches have belief in the player they call “Moose.”

“It’s a bonus to have a guy with his background and his experience,” coach Alain Vigneault said after Wednesday’s training-camp session in Voorhees.

Elliott, 35, a 13-year veteran, was sharp Wednesday.

“I’ve felt kind of better and better each day,” he said. “It’s just about getting back that competitiveness and battle level. I think we’ve done a good job of trying to ramp things up.”

Elliott helped keep the Flyers afloat when Hart was sidelined with a lower-abdominal injury for nine games in the second half of the season. Elliott played in seven of those nine games, going 5-1-1 with a 2.06 GAA and .916 save percentage.

With the 21-year-old Hart again sidelined, Elliott said that it doesn’t affect his mindset and that, with the season’s restart getting closer, his intensity level is picking up whether he is the starter or the backup.

Vigneault said he was not concerned by Hart’s injury. He said that Hart, health permitting, will be the starter when the playoffs start, but that he had confidence in both goaltenders. Elliott will get some action in the round-robin, seeding tournament -- three games before the playoffs begin.

Four miss camp

Center Sean Couturier, who was at the hospital with his expecting wife, was one of four players who missed the camp session Wednesday.

Hart, forward Connor Bunnaman, and goalie Kirill Ustimenko also missed practice. Because of NHL guidelines, general manager Chuck Fletcher couldn’t give specifics and was able to say only that the three players were “unable to participate.”

Power-play time

For the first time in Training Camp 2.0, the Flyers worked on their power play and penalty kill Wednesday. The units played a major role as the Flyers won nine straight late in the regular season.

The top power-play unit had Morgan Frost filling in for Couturier, and it also had Claude Giroux, Travis Konecny, Jake Voracek, and Ivan Provorov.

Kevin Hayes, James van Riemsdyk, and Matt Niskanen were the mainstays on the second unit, which had Travis Sanheim rotating with Shayne Gostisbehere, and Nic Aube-Kubel rotating with Joel Farabee.

Niskanen plays on both the power play and penalty kill. He said the power play “takes a little bit longer to get back in a rhythm” and the penalty kill is “just about habits, and that comes back quickly -- what you need to do, your reads and your pressure moments. I think that will come back quickly.”

Breakaways

Elliott on Couturier: “I feel bad for him. You’re having a kid and you’re having to leave right away [for Toronto]. It’s such a magical moment and you want to be a part of it as much as you can.” ... Teams can dress 22 players (instead of the usual 20) for exhibition games, Vigneault said. The Flyers’ lone exhibition will be 4 p.m. Tuesday against Pittsburgh. It will be televised by NBC Sports Philadelphia+.