PHILADELPHIA (973espn.com) - Much is made about Jim Schwartz's rotational system when it comes to the "engine" of his defense.

This season the vaunted defensive line mixing and matching has really only existed at defensive end where Brandon Graham, Derek Barnett, Michael Bennett, and Chris Long offer the defensive coordinator a deep and impressive list to cull from no matter the stakes or the situation.

Inside, however, the bench has been shortened so to speak without Tim Jernigan, who is still on the NFI list while recovering from offseason back surgery.

To date, All-Pro Fletcher Cox had played in a hefty 87.2 percent of the Eagles' defensive snaps through three games, 163 in total and more than the other three interior linemen Schwartz has played combined.

Veteran Haloti Ngata has been on the field for 80 reps as a two-down run stuffer with Destiny Vaeao stepping in as the third tackle (62 snaps) and undrafted rookie Bruce Hector getting an opportunity here and there (12 snaps).

"So far I played a few," Cox admitted. "The defense as a whole hasn't been playing a whole lot. I think last year my average was 50 snaps a game, kind of around that area there. Feel it’s still the same for me, especially with a three man rotation we have going on right now and coach being smart about it asking me if I’m OK, not trying to wear me down. It’s a long season and right now it’s early in the season."

Coming into this season Cox has never played more than 81 percent of the team's defensive snaps. Last season, the number was a far more manageable 59 percent with Jernigan and Beau Allen available and contributing.

Schwartz, though, added some context to those numbers.

"We're not playing a ton of snaps on defense," Schwartz said Tuesday. "We had 60 [snaps] basically the last couple games. So even if the percentage is up -- his snap count is up, but it's not so drastic."

Remember that back in 2015 Chip Kelly was still the head coach in Philadelphia and the defense was always on the field with Cox seeing 983 snaps in 2015 and 921 the year before that. Even at his current rate of playing almost nine out of every 10 snaps, Cox would be at 869 by the end of the season.

"I can play 50, 55 snaps, 60 sometimes when they need me," Cox insisted. "Most of the snaps some of them may be penalties so kind of take that one back and not count it as a full rep, especially pre-snap penalties. I know I can handle it, but we have other guys like Destiny and Bruce Hector who can come in, they’re fresh, know the scheme and know what to do."

The goal is to certainly lighten the load a little bit as the year progresses.

"[The workload] might not be ideal for us as a group as the season goes on, but if it's something we have to do in the short-term, then that's fine," Schwartz explained. "I think that [we] get contributions out of a lot of the other guys. Missing [Eagles DT] Timmy [Jernigan] out there, and he's a good multi-dimensional player. Good pass rusher. Good run stopper. One of the reasons we like him."

Every now and again reporters spot Jernigan around the NovaCare Complex rehabbing for his return and if he is able to make it back for say the second half of the season, things should fall into place.

Until then more snaps for Graham and Bennett inside during obvious pass-rushing situations could be the way to at least make things a little easier on Cox, who has been the Eagles best player so far.

"A lot of the other guys were sort of mixing and matching a little bit more [against the Colts], trying to use their strengths, use some guys a little bit more in run situations or pocket pushing pass rush situations," Schwartz said. "Doesn't necessarily have to be a run to get some of those guys out there.

"And then working probably expanded our use of defensive ends at defensive tackle with more snaps for [Eagles DE] Brandon [Graham] and [Eagles DE] Michael Bennett in there."

-John McMullen covers the Eagles and the NFL for 973espn.com. You can reach him at jmcmullen44@gmail.com or on Twitter @JFMcMullen