What Davis is counting on is that many of his returning starters will be stepping up their play now that they have a year in his system under their belts, a year of playing together. Less thinking, quicker decisions. Better communication. Fewer blown-coverage and wrong-gap mistakes.
An argument can be made, though, that many of Davis' players have no place to go but down. Can we really expect any more than eight sacks from soon-to-be-32 Trent Cole? What effect will last season's nearly 1,200 snaps have on linebacker DeMeco Ryans' 30-year-old body?
Can anyone expect cornerbacks Cary Williams and Bradley Fletcher to play much better than they did last year? And how is Brandon Boykin going to improve on six interceptions?
What more can linebacker Connor Barwin do that he didn't do last season? Operate the scoreboard? Sing the national anthem?
There are two players, though, who haven't even scratched the surface of their potential yet, who could elevate Davis' defense. One is defensive end Fletcher Cox. The other is inside linebacker Mychal Kendricks.
Cox is handcuffed a bit by Davis' scheme. He is best suited to be a three-technique tackle in a 4-3 alignment. But he is a two-gap end in Davis' 3-4 scheme, which means he spends a good portion of his time occupying blockers so that Kendricks and Ryans and Barwin and Cole can make plays.
Kendricks, though, is in the perfect scheme and playing the perfect position to maximize his skills and develop into a Pro Bowl-caliber playmaker for Davis.
Like the rest of the Eagles' defense, Kendricks struggled early last season, but still had a pretty good overall year. The 5-11, 240-pounder, who was taken in the second round of the 2012 draft, finished second on the team in tackles (137), third in sacks (four) and second in interceptions (three), and led the league in fumble recoveries (four).
Kendricks may not be the tallest linebacker in the league, but he's one of the most athletic, which is why the Eagles think he has such a high ceiling. He ran a 4.41-second 40 at the 2012 scouting combine, the fastest time by any linebacker.
"When we first started, if you look at where we were as a defense and as a unit of linebackers in August and where we grew into by January, my [position] room made a lot of progress," said Rick Minter, who coaches the Eagles' inside linebackers.
"Now, the defense played pretty consistently all year. Mychal, he really was just 12 months away from being a rookie last year. He played 1 year in a system that may or may not have operated efficiently for his skill set. And all of a sudden, he was earning his stripes as a full-time starter in the NFL."
Kendricks played both inside and outside linebacker in a 3-4 scheme at Cal. As a rookie with the Eagles, he found himself playing a sitting-duck outside linebacker in an underperforming, wide-nine 4-3. Now, he's back inside in a 3-4.
"I like where I am now," Kendricks said. "I played outside in a 3-4 at Cal for a year and I killed it [13 sacks in 12 games his junior year]. But I'm happy where I am. Wherever they ask me to play, I'm going to try my best, try my hardest. But I do like my position and where I am now."
Kendricks' greatest enemy last season was inconsistency. He was a wild stallion who would make an All-Pro play one minute and an oh-no play the next. But there is no question that the talent is there.
"Mychal has to play a lot of roles for us," Minter said. "He's an inside thumper when needed, but he's also our dime linebacker. He gets the heavy lifting to do in covering their best guys. Very marketable tight ends like your Jason Wittens, like your Jimmy Grahams. That's a tall order.
"Did he get better throughout the course of the year? Yes. He became pretty darn good. He's a productive player. You have to get the rough spots [ironed out]. He has to become a better tackler, a better man-cover guy.
"But he was very productive. He had a lot of tackles. He made impact plays. He causes fumbles, recovers fumbles, gets interceptions. He gets sacks and lost-yardage plays. He just needs to become a more consistent part of our defense."
One of the things Andy Reid liked most about Kendricks when the Eagles drafted him was his blitzing ability. But that talent was wasted as a rookie. Kendricks blitzed just 37 times in 955 snaps in 2012.
Last year in Davis' scheme, he rushed the passer 134 times in 1,022 snaps. He was very effective, with six quarterback hits and 12 hurries in addition to his four sacks, according to Pro Football Focus, for a team that finished 31st in the league in sacks per pass play.
Kendricks' size was viewed as a distinct disadvantage coming out of Cal. And in coverage, against taller tight ends, it probably is to a certain degree. But he thinks it helps him against the run.
"They don't see me sometimes," he said. "I can definitely slip [blocks].
"I'm always going to be around the ball. That's my thing. That's my niche. Speed. Because I'm a smaller 'backer, I can get in between crevices and little fits. I'm lower to the ground. So I can get to the ball a little faster than taller guys."
Early last season, after playing poorly in the Eagles' first couple of games, Kendricks got a call from his old Pop Warner coach, Howard Lett.
He gave Kendricks a long-distance pep talk. Told him he needed to take the field with full confidence, like he owned it.
Ever since then, that's what Kendricks has done. He has embraced the good plays he has made and shaken off the bad ones. There is no one he fears.
Now, he's ready for a breakout season. Now, he's ready to help the Eagles' defense carry its share of the load.
"We're a hundred times better than we were last year," he said. "A hundred times. I don't say that lightly. We're so much further along than we were last year. The second year with the same guys, the same coaches, it feels good."
On Twitter: @Pdomo