The Pittsburgh Penguins will be without a huge piece of their offense for at least the start of a season-defining four-game road trip after Bryan Rust was injured in the third period of a wild 7-6 win over the Philadelphia Flyers on Sunday.

Despite the key victory, the Pens lost yet another top-line forward, with Rust joining Jake Guentzel on the shelf. The 31-year-old will not play against the Vancouver Canucks on Tuesday, and is still being evaluated in Pittsburgh.

Rust is third on the team with 18 goals, behind just Sidney Crosby and Guentzel. The 10-year veteran has been especially potent as of late, picking up seven goals in his last eight contests. Up to 36 points in 42 games, he's irreplaceable in the Pens' top-six.

Both Rust and Guentzel's ailments are devastating to the playoff chances in Pennsylvania, and if Rust's injury is serious, it could force Kyle Dubas to sell at the Mar. 8 NHL Trade Deadline.

“Rust's injury could be a significant blow to the Penguins' hopes of climbing the standings to get back into a playoff position on their four-game road trip. If they can't do that, it increases their chances of being a seller before the deadline,” wrote on Monday.

“If the Penguins don't have Rust too, that means two-thirds of the top line that Sidney Crosby centers will be out, significantly impacting their ability to climb in the standings, which could cement their position as a seller ahead of the deadline.”

It's looking more and more likely that Jake Guentzel will be traded

The Penguins enter Tuesday a full seven points back of the Flyers for the No. 3 berth in the Metropolitan Division, and their upcoming road trip will basically answer the question as to whether Dubas will sell at the deadline.

If the trip doesn't go well — and without Rust and Guentzel, it becomes even more difficult — the latter is likely to be moved. Although Guentzel travelled with the team to Vancouver, he isn't eligible to come off injured reserve until Mar. 10. Meaning, he may have already played his last game in a Pittsburgh Penguins uniform.

Each of the next four games are absolutely monumental for this club, beginning against the Western Conference-leading Canucks at Rogers Arena on Tuesday.