The Pittsburgh Penguins registered the fifth loss of their past eight contests on Sunday night, getting dropped 6-2 at home by the rival Philadelphia Flyers.

Injuries managed to stall the Penguins once again, as top-line winger Conor Sheary was forced out of the tilt and defenseman Brian Dumoulin was nearly sidelined as well, leaving after taking an elbow to the head but eventually returning.

There's no question the Penguins' extensive list of injuries has taken a significant toll on them, with seven of their usual skaters officially on the shelf. One key result of that persistent trend? Pittsburgh is lacking that coveted late-season momentum that fed the 2015-16 squad.

Recall that momentum served as one of the club's key advantages leading up to its Stanley Cup run last year. After stumbling through the first half of 2015-16, the Penguins found new life once Mike Sullivan was installed as head coach in mid-December.

From Jan. 1, 2016 on, Pittsburgh put together a dominant 30-11-4 record, leading the league in goals and allowing the sixth fewest as well, before rolling through the playoffs.

This season, it's been an entirely different story in the Steel City.

With Sunday's loss to Philadelphia in tow, the Penguins have now allowed four goals or more in five of their past eight tilts.

Compare that to 2015-16, when the Penguins let in four goals just twice over their final 23 games of the year.

In fact, they let in four or more goals just 10 times during Sullivan's entire 54-game tenure to close out 2015-16.

This time around, Pittsburgh has allowed four or more goals 25 times through 75 games, their injury-riddled blue line surely playing a role in that shift.

The Penguins still have enough talent to potentially repeat, and all signs point to them getting the bulk of their injured talent back for the postseason, but as of right now, they look like a significantly different team than the one that lifted the Cup last spring.

With only a handful of games remaining, the Penguins are running out of time to get healthy bodies back on the ice and pick up some steam, as the 82-game mark is fast approaching.

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