PHILADELPHIA -- It's not hard to figure out who deserves blame for the Penguins' 6-3 loss at the Wachovia Center yesterday.

No, not coach Michel Therrien, even though he decided that No. 1 goalie Marc-Andre Fleury, who had missed the previous 12 games because of a groin injury, was healthy enough to be in uniform, but opted against playing him.

Not the special teams, even though Philadelphia scored on 4 of 6 power plays, while the Penguins went 1 for 4 with the man-advantage.

And not even all the guys who lost so many one-on-one battles and were outhit, outworked and outhustled for much of the afternoon.

No, responsibility for this one falls squarely on the NHL's schedule-maker. Partly because this was their seventh game in the past 11 days, partly because he had the temerity to force the Penguins to play someone other than the New York Islanders.

Which, if recent events are taken at face value, is the only club the Penguins (16-10-4) can reasonably expect to beat these days.

The loss to the Flyers was their fourth in the past five games and dropped them into third place in the Atlantic Division. They are two points behind Philadelphia and were four in back of the first-place New York Rangers, pending the outcome of New York's game against Carolina last night.

And while the Penguins were adamant that fatigue shouldn't have been a factor yesterday, how else to explain why they sleep-walked through most of a game against a divisional opponent that might just be their most-hated rival?

"It was just a matter of, from the drop of the puck, they had a better work ethic than us," defenseman Mark Eaton said. "That's inexcusable."

And pretty obvious, given the Flyers' decided advantage in virtually every facet of play.

"I didn't really think it was X's and O's," defenseman Brooks Orpik said. "They competed a little harder than we did early on. Whether it was the schedule or not, I think we had a better effort in us than we gave."

The Penguins are scheduled to have today off, which likely is good. Not only because they could use some rest, but because Therrien and his staff will need at least 24 hours to find everything in the game tape that troubles them.

"We were not good in every department," Therrien said.

Yeah, but at least they were consistent. They were almost as sluggish in the final minutes of the game as they had been in the early ones. And most of the ones in between.

The Flyers effectively put the game away when Joffrey Lupul (5:49) and Mike Knuble scored power-play goals in the first period. Knuble's was the first of several Philadelphia got after winning individual battles in front of Penguins goalie Dany Sabourin.

"We probably could have done a better job in front of our net," Orpik said.

"That just goes back to competing."

When it became 2-0, the Wachovia Center crowd seemed to conclude (quite correctly) that the Penguins didn't represent a significant threat. That allowed most of the fans to put their full energies into jeering Sidney Crosby -- a growth industry on this side of the Commonwealth -- and, in keeping with local custom, offering a festive assortment of chants revolving around a word that sounds a lot like "socks."

Most of which, truth be told, offered a fairly accurate assessment of the visiting team's performance.

Although Jordan Staal revived the Penguins briefly by deflecting an Alex Goligoski feed past Flyers goalie Martin Biron at 7:08 of the second, Mike Richards and Scott Hartnell countered for the Flyers over the next 5 1/2 minutes to make it 4-1.

Knuble pushed it to 5-1 before third-period goals by Eric Godard and Ruslan Fedotenko sandwiched one from Flyers center Jeff Carter to complete the scoring.

"We wanted, definitely, a better effort," Crosby said. "These are big games, standings-wise, and these are always intense games. You should be ready for these ones."

Or awake, at least. Philadelphia certainly seemed to be, which was just one of many things that separated the Flyers from the Penguins on this day.

"I don't know what you'd call it," Godard said. "But we didn't have it."