Rookie center Nolan Patrick, the No. 2 overall selection in the June draft, suffered a possible concussion when he was knocked into the glass head-first in the second period Tuesday night.

It wasn't the only headache the Flyers experienced in their 6-2 loss to the Anaheim Ducks at the Wells Fargo Center.

The new defensive pairings, necessitated because of a leg injury suffered by Andrew MacDonald on Saturday, looked out of sync from the start. The passing was sloppy, the power play was 0 for 6, and goalie Brian Elliott struggled as the Flyers lost for the seventh straight time to Anaheim in games played at the Wells Fargo Center.

"They're a big, physical team and they come hard at you," said Sean Couturier, who scored a pair of goals in the defeat. "But at the same time, we have to be a little smarter. The ice is pretty bad right now and we know it, but we have to make better decisions [with the puck]. We were making risky plays."

Shayne Gostisbehere said the ice was "horrendous," but added, "it's not an excuse. Just something we have to deal with. … The big thing isn't about the ice; it's how we played."

Anaheim pulled away from a 1-1 tie with a 3-0 second period that included a power-play goal by Nick Ritchie.

"We have to do a better job of keeping our composure; we weren't happy with some of the calls, and I was probably the first one to kind of lose my composure," said Claude Giroux, who was in the penalty box for tripping when Ritchie scored.

All three pairings were changed after the loss of MacDonald, who is expected to miss four to six weeks. He had been on the top pairing with Ivan Provorov.

In the first two periods Tuesday, Provorov was paired with Robert Hagg, Gostisbehere was with Radko Gudas, and Brandon Manning was with Travis Sanheim.

All struggled as the Flyers fell into a 4-1 hole in the first 40 minutes.

"I think you have to play a couple games to get some chemistry," Gostisbehere said. "… But as a team, we could have played a lot better tonight. It didn't look like we had that extra gear."

Coach Dave Hakstol reset the pairings in the third period to get some familiarity — Provorov was with Sanheim, Hagg was reunited with Gostisbehere, and Manning was with Gudas — but it didn't matter.

Couturier's second goal of the night got the Flyers within 5-2 with 8:06 to go. Sanheim recorded his first NHL point on the goal, Couturier collected his 200th career point, and Jake Voracek notched his 500th career point.

Ondrej Kase scored two goals, including a penalty shot to make it 6-2 late in the game, to pace Anaheim (4-3-1). Kase's brother, David, is a Flyers prospect who is playing right wing in Sweden.

The Flyers went 3-2 on the homestand, and they will play in Ottawa on Thursday, probably without Patrick, who was checked into the corner boards by fourth-line winger Chris Wagner with 17:25 left in the second period and the score tied at 1-1. No penalty was called on what appeared to be a clean shoulder-to-shoulder hit.

A wobbly Patrick had to be assisted to the locker room, where he was undoubtedly administered a concussion test. He did not return to the game and watched the third period from the press box.

The Flyers said they would know more on Wednesday.

If Patrick is sidelined, Jori Lehtera may center the third line. Lehtera, a natural center, played left wing on the third line Tuesday.

Defenseman Brandon Montour blew past Travis Konecny and got behind Manning before beating Elliott with a right-circle wrist shot, giving the Ducks a 2-1 lead with 14:20 left in the second. About 4½ minutes later, Ritchie made it 3-1, scoring on a power-play rebound.

With 1:43 left in the second, Rickard Rakell got behind Hagg and converted a feed from Ryan Getzlaf to put the Ducks ahead, 4-1.

Earlier, a defensive-zone turnover by Konecny led to Kase's goal with 1:38 left in the first, knotting the score at 1-all.

The first period also saw Anaheim's Kevin Bieksa deck Gudas with a righthanded punch 1:24 before Kase's goal.

The Flyers (5-4) had been unbeaten when scoring the game's first goal but slipped to 5-1 in those situations.

"It's a long season, 82 games. Games like this are going to happen," Giroux said. "It's how we deal with it" that is important.