While the Eagles' starting unit is in place and helped the team tie for the league lead in sacks last year, the front four is aging and has few young players in the pipeline.
At defensive end, Trent Cole is 29, and Jason Babin is 31. Brandon Graham, the team's top pick in 2010, is still a mystery, having made just 13 starts and being limited so far by a knee injury.
Defensive tackles Cullen Jenkins, 31, and Mike Patterson, 28, each played well last season, but neither provides the consistent disruptiveness the Eagles would love to have on the interior. There are no difference-making pass-rushers rising up behind them.
The Eagles have used five first- or second-round picks on defensive linemen in the last seven years - and if they want more, the tackle class is the deepest in the draft. There's a good chance a tackle will be the best available player when the Eagles pick.
"Throughout the draft, there are defensive tackles who can play," said general manager Howie Roseman.
He'll be looking for prospects who can get after the NFL's prolific passers.
"[For] our defensive tackles, we're not just looking for guys who can hold the point and play the run, that's not what we're looking for there," Roseman said. He later added, "We're looking for guys who put pressure on the quarterback. We believe this is a passing league and that's something that is important to us."
And, of course, with maniacal line coach Jim Washburn sending wave after wave at quarterbacks, linemen need the "motor" the Eagles covet.
"There are very specific guys who are going to excel in this system. You have to be able to play hard because you are going to be running," Roseman said.
That would seem to dampen the prospects here for end Quinton Coples and tackle Dontari Poe, two players who have been cited for failing to turn immense talent into production.
Athletic and explosive Mississippi State defensive tackle Fletcher Cox would seem to perfectly fit the Washburn mold, but he could be gone well before the Eagles' No. 15 pick.
Poe, Michael Brockers, and Jerel Worthy are other potential first-round talents.
The end class is not deep.
Melvin Ingram, of South Carolina, is the top edge rusher, followed by a mix that includes Courtney Upshaw, Whitney Mercilus, and Chandler Jones. Some of them may end up as 3-4 outside linebackers.
The Eagles already have a strong line, but when it comes to quality or quantity there, they want both.
Contact staff writer Jonathan Tamari at 215-854-5214, firstname.lastname@example.org or follow on Twitter @JonathanTamari.