The Flyers are 1-1-1 in the preseason after Saturday’s 3-1 win over Washington.

Yes, the Flyers played their regulars (except for Carter Hart) while the Capitals used their “B” team. Still. there were encouraging signs.

Here are five observations from the victory at the Wells Fargo Center:

Defense is solid

The Caps were missing Alexander Ovechkin, T.J. Oshie, Nicklas Bäckström, and John Carlson, among others, and will be a more difficult challenge down the road. But that doesn’t mask the solid play of the Flyers’ rebuilt defense.

All three new pairs were together at the same time for the first time in the preseason, and the duos -- Ivan Provorov and Ryan Ellis, Travis Sanheim and Rasmus Ristolainen, and Keith Yandle and Justin Braun -- played well and had surprisingly good chemistry for this early in the preseason. Ristolainen and Ellis bring some much-needed snarl to the D.

Covering each others’ backs

Led by Ristolainen’s five hits, the Flyers played with lots of physicality. It was also a good sign that in scrums/fights, Derick Brassard and James van Riemsdyk stood up for Provorov, and Ristolainen did the same thing for Joel Farabee.

Playing with aggression and sticking up for your teammates are two traits that weren’t on display enough last season.

“That is part of being a team here — you’ve got to stand up for one another,” coach Alain Vigneault said. “You’ve got to be smart about it. I think that shorthanded penalty in the third was the right thing to do. You’ve got to find a way to kill those, and we did find a way to do it. Good for our group of players to stand up for one another, and it’s got to continue.”

Frost’s strides

Morgan Frost, who had shoulder surgery in January, struggled to shake the rust Thursday in Boston when he played in his first game in eight-plus months.

The 22-year-old center was much better Saturday as he was stronger on the puck, created some scoring chances, and was effective on the forecheck.

“I saw a couple flashes,” Vigneault said. “Young man hasn’t played hockey in a year and is coming back from a serious injury. He is going to get a chance to play some more games and hopefully every game and every shift he gets better.”

The Flyers need Frost to continue to make strides because Kevin Hayes won’t play until November after recently undergoing abdominal surgery.

Jones rebounds

After Martin Jones’ shaky performance in half a game in Boston — he allowed three goals on 11 shots — the 6-foot-4 goalie bounced back and stopped 21 of 22 shots vs. the Capitals.

“It was good. The boys were talking out there,” Jones said of the defensemen. “... Definitely felt more comfortable out there, and we’ll continue to get better.”

Yandle makes PP better

New defenseman Keith Yandle makes the Flyers’ power play better with his uncanny ability to get pucks through to the net, or with his slick passing to a teammate down low.

The PP quarterback, Yandle helped set up Claude Giroux’s early power-play goal Saturday to tie the score at 1-1.

“We’re getting on the same page,” Giroux said. “I mean, all the guys have played together on the power play before except Keith, but he moves the puck well and gives it to the right guy. For us, we just have to keep building on it, keep working on different plays and make sure we get momentum for the team.”

Breakaways

Carter Hart will get the call Monday as the Flyers host Boston (2-1-1). Hart stopped 17 of 18 shots against the New York Islanders on Sept. 28 in his lone preseason performance to date.