Let's face it. We don't have the slightest clue at this point what kind of production they will get from the quarterback position because we don't even know who the hell the quarterback will be, and probably won't know until the middle of August.
We don't know whether DeSean Jackson will once again be the big-play threat he was in his first 2 1/2 NFL seasons or the often-invisible underachiever he's been in the last 2 1/2.
And despite the fact that seven of their nine veteran free-agent signings and five of their eight draft picks happened to be defensive players, it still remains to be seen whether the defense will be be appreciably better than it was a year ago when it finished 29th in the league in points allowed.
But with the return to health of Peters, Herremans and Kelce, and the addition of first-round tackle Lane Johnson, the offensive line has a chance to be very, very good.
"If Johnson is as good as they think he is and the other guys come back healthy and stay healthy, they could have the best offensive line in the division and maybe one of the best in the league," said NFL Network analyst Brian Baldinger, who played 11 seasons as an NFL offensive lineman.
"If that's the case, they'll be able to run the ball really well, which will go a long way in allowing them to do what Chip wants to do with that offense."
Because they finished a disappointing 8-8, people tend to forget that the Eagles' offensive line was one of the better units in the league the last half of the 2011 season.
Peters, the team's freakishly athletic left tackle, was a runaway All-Pro. Kelce, a sixth-round rookie, started 16 games and had offensive-line coach Howard Mudd comparing him to six-time Pro Bowler Jeff Saturday.
Herremans made a seamless transition from left guard to right tackle. And Evan Mathis, a way-under-the-radar free-agent signee, developed into a solid-as-a-rock left guard.
Even with 2011 first-round pick Danny Watkins struggling at right guard, the line helped running back LeSean McCoy rush for 1,309 yards and a franchise-record 17 touchdowns.
They couldn't wait to take it to the next level last season, but then everything went to hell. First, Peters tore his Achilles' not once but twice that spring. Then Kelce was lost for the year. Then Herremans.
Without those three, the offense sputtered. McCoy's rushing TDs plummeted from 17 to two, his rushing average from 4.8 to 4.2.
Two years ago, Peters was a big reason McCoy made All-Pro. The Eagles running back averaged 5.0 yards per carry and had six TDs on runs to Peters' side. Last season, without Peters, McCoy averaged only 3.2 yards per carry to the left side, with zero TDs.
In 2011, the offensive line allowed only 23 sacks and 34 hits on the quarterback. Last year, without Peters, Kelce and Herremans, it gave up 33 and 66, according to Pro Football Focus.
"We're very excited," Kelce said yesterday after participating on a limited basis in the first of the Eagles' 10 spring OTAs, which will be followed by a mandatory 3-day minicamp June 4-6 before the team takes some pre-training camp R&R.
"We've got a new piece in Lane. But we felt that 2 years ago, we were starting to really come together toward the end of the season. We were excited for last year, then it seemed like everybody went down.
"I think when this line is healthy and everybody is there, we have a very dominant offensive line."
Johnson, the fourth overall pick in last month's draft, is expected to be the Eagles' season-opening starter at right tackle, with Herremans moving back inside to guard.
Herremans was at right guard yesterday, but second-year man Dennis Kelly, who started 10 games last year, was taking the first-team reps at right tackle rather than Johnson.
Don't be alarmed. Asked by a reporter what we should make of Johnson running with the second-team, Chip Kelly said, "It's May 13, so I would make that of it. I don't think we play the Washington Redskins until sometime in September."
Said Kelce: "At some point, [Johnson] will be thrown in there with the starters. I don't know when that'll be. But you don't draft somebody fourth overall without the anticipation of him starting some games for you. I think once they feel he understands the offense well enough, understands the techniques and all of that, I think that's when they'll put him in there."
Herremans has 100 career starts. Seventy-one of them have been at left guard. He had never started an NFL game at right tackle until being moved there 2 weeks before the start of the 2011 season.
Since he was given a contract extension after the 2011 season that pays him like a starting tackle, Herremans doesn't mind sliding back inside to either of the guard spots.
"I don't think anything is set in stone at this point," he said. "But right now, they've got me working at right guard, and I'm gonna work on being the best right guard I can."
The Eagles' likely season-opening group right now would have Peters at left tackle, Herremans and Mathis, who is out until training camp after having clean-out surgery on his left ankle, at the two guard spots, Kelce at center and Johnson at right tackle, with Watkins, Kelly and Dallas Reynolds as the probable top backups.
All five starters are extremely athletic and seem to fit well into the zone-running game Kelly is expected to employ.
"They like to utilize us in space and they like to get us to the second level," Kelce said. "So that's all very similar to what we were doing [under Andy Reid]."
A good portion of McCoy's rushing yards in 2011 came on zone stretch plays and out of spread formations. The athleticism of this unit also made the Eagles one of the league's most dangerous screen teams 2 years ago, despite the fact that screen passes never have been one of quarterback Michael Vick's strengths.
"It's a good mix of everything," Herremans said. "We've got some power, some zone, some outside-zone, some man plays. A little bit of everything. It's a big thing for us to be well-rounded."
Said Kelce: "For us, this system still tries to use the athleticism of the offensive linemen, as you saw when they drafted arguably the most athletic offensive lineman in the draft [Johnson]."
Interestingly, Kelly's offensive-line coach, Jeff Stoutland, came from what was primarily a power offense at Alabama. Most of his offensive linemen in Tuscaloosa were mashers rather than the athletic zone-blocking types he's coaching now.
"[Alabama] would do some inside-zone stuff, but they didn't do too much outside-zone," Kelce said. "It was mostly a man scheme on the outside perimeter plays.
"This is a different style offensive line than he had at Alabama. He understands that. I think he knew that coming in that it was going to be a little bit different.
"The good thing about Stout is that he allows his offensive linemen to use what works for them. Even though he tries to teach his technique and things, if you're doing something that's working, and he likes the way it works mechanically, he'll let you do it."
Baldinger sees a big season for this unit if it stays healthy.
"They have a very good chance of being really, really good up front," he said. "Like they were in the second half of the 2011 season when I thought they were just about as good as any team in the league up front. Now, you add Lane Johnson to the mix.
"The sky's the limit."
On Twitter: @Pdomo