The Eagles don't have another Fletcher Cox they can just plug in at defensive tackle next to Tim Jernigan on Sunday against the Los Angeles Chargers. If they did, Cox probably wouldn't be making a team-high $102.6 million over six seasons.

They can play Brandon Graham inside, against a team that hasn't really tried to pound the ball so far this season, and fill in for Graham outside with someone like Chris Long or first-round rookie Derek Barnett. But the most likely Eagle to get more work from Cox's absence is fourth-year defensive tackle Beau Allen.

Allen is a very different player from Cox; at 6-foot-3, 327 pounds, he's an inch shorter and 17 pounds heavier. Cox has 30.5 career sacks. Allen has one career sack, in 51 games, since arriving as a seventh-round draft choice in 2014 from Wisconsin.

But Allen isn't the kind of backup player you can just dismiss as a spare body. He was a fringe draft prospect because a lot of draft evaluators thought he was strictly a space-eating, 3-4 nose tackle. Yet the Eagles transitioned to 4-3 in 2016, and unlike some projects from the Chip Kelly era, Allen transitioned right along with them. He logged 50 snaps last week against the Giants, many after Cox went down with a calf strain near the end of the second quarter. Allen, 25, had only seen that kind of playing time on three previous occasions in his NFL career.

But regardless of what Allen does Sunday against the Chargers, he might have already accomplished his most impressive feat of 2017 – getting back several weeks ahead of schedule from the torn pec tendon he suffered working out in April.

"He's one of those guys that's just self-motivated, he's a self-starter. Very driven," Eagles coach Doug Pederson said. "I think the first [few games of the season], he was just getting his legs back and working into football game condition. You're seeing that, you're seeing more explosiveness off the ball. He's a big guy, he can penetrate a gap, he and Tim Jernigan are both those kinds of guys."

The injury could have been a career-changer for Allen, who was in line to become a starter for the first time, following the departure in free agency of Bennie Logan. Management was talking to his agent about a contract extension. Then Allen needed surgery – a just-starting-to-fade red scar runs down his beefy right shoulder – and the Eagles traded for Jernigan, an established starter for the Ravens, though the team said the timing was coincidental. So far, there has been no Allen contract extension.

"I'm a big meathead, so to speak. I like working out a lot and I take a lot of pride in that. I felt a little betrayed by the fact that I got hurt in the weight room," Allen said. "That's just how it goes, man; you can't dwell on it that much … That's in the rearview mirror now. I'm getting all these opportunities, and I'm really excited about it."

Allen, originally scheduled to return a few weeks into the season, instead was back for the final preseason game.

"I pride myself on being dependable, on being there for my teammates when they need me. I don't ever want to be on the outside looking in, and that's how it feels a lot of times when you're injured," Allen said this week.  He set a school record by playing 54 career games for Wisconsin, where Allen was a three- time Academic all-Big Ten selection. "I definitely pushed myself in the rehab process to get back as fast as possible. It's nice to be back with the guys, and it feels like was so long ago that I was on IR, but it was only three weeks ago."

Allen is a solid defensive tackle, but Cox is a disrupter, who draws double teams.

"I hold myself to a very high standard. I like to think that I'm a very good pass rusher, but obviously, I haven't posted the same numbers as Fletcher Cox or BG [Brandon Graham]," Allen said.  "I have a lot of faith in my ability. I don't really worry about things like that. I just know if I keep playing as hard as I can, to my ability, everything will work out.

"I'm a little heavier than our other defensive tackles here. But I consider myself a powerful, explosive guy, and I think my teammates would probably say the same thing."

Indeed, they would.

I respect Beau, man," Graham said.  "Every time you see him, he's always got his notebook open, taking notes. He's always prepared, always ready."

And, Graham added, "He can move."

Also not making the trip will be another defensive tackle, Destiny Vaeao, out since the opener with a wrist injury. That would have left Jernigan, Allen and sixth-round rookie Elijah Qualls as the only true defensive tackles available, so just before flying out Saturday, the Eagles promoted defensive tackle Justin Hamilton from the practice squad and waived safety Trae Elston. Qualls, inactive for the opener, got nine snaps at Kansas City, 14 against the Giants.

"There's a lot of flexibility here," Pederson said Friday. "We haven't made a final decision yet on [how to handle being so thin at DT]. We'll get through today's practice, have a few more conversations with [defensive coordinator] Jim [Schwartz] and [defensive line coach] Chris [Wilson], and go from there."