"You knew when you watched him in college that he had the chance to be something special," Eagles tight ends coach Ted Williams said. "He's one of the best route-runners I've ever seen. He takes a lot of pride in that.
"He has a lot of confidence. He's hard to defeat, because he doesn't take defeat very well. He feels, 'You can't cover me.' "
Ertz was eased into the offense as a rookie last season by coach Chip Kelly. He played 36 percent of the offensive snaps in the Eagles' first eight games and 45 percent in the final eight.
Finished with 36 catches - 25 for first downs - for 469 yards and four touchdowns. All four of those scoring catches came in the second half of the season. He also had a touchdown reception in the Eagles' playoff loss to New Orleans.
"You have to have confidence in this league," Ertz said. "Everybody's so good. If you don't have the confidence, that's half the battle. You're going to be defeated before you even start.
"I take every rep personally. If somebody beats me, I'm going to take that personally. I want to be great. That's my goal each and every day I step out on the field. I want to prove to myself and everybody else how good I can be, and I'm willing to work as hard as I need to to achieve that goal."
Without Jackson, one of the league's most dangerous vertical threats, the Eagles' passing game is expected to undergo a slight transformation this season.
Case in point was last week's preseason win over the Steelers. The Eagles had four touchdown drives of nine plays or more in the first three quarters of that game. That's just five fewer than they had all of last season, when they led the league in touchdown drives of six plays or fewer.
So, look for fewer deep balls and more bubble screens and slants by the wide receivers and more screens and wheel routes by running backs LeSean McCoy and Darren Sproles.
And a much bigger role in the passing game for Ertz and the Eagles' other starting tight end, Brent Celek.
Celek, Ertz and the Eagles' No. 3 tight end, James Casey, combined for only 71 receptions last season, though 10 of them resulted in touchdowns. Despite playing 77 percent of the snaps, Celek was targeted only 51 times and caught only 32 passes. Both of those numbers were his lowest since '08, his second year in the league.
As Ertz gained experience last season, Kelly went to more two-tight end sets. The Eagles used two- and three-tight end formations only 17.5 percent of the time in the first eight games, but 37.7 percent in the last eight.
Two-tight-end sets generally are regarded as a run formation. Defenses usually use their base package against it. But the Eagles passed nearly 40 percent of the time with "12" personnel (one back, two tight ends and two wide receivers) on the field last season.
"There are no keys to what we're going to do [with '12' personnel]," Williams said. "In many situations, when a team puts two tight ends on the field, it's a run formation. Not necessarily with us.
"We'll throw the ball with two tight ends in tight formations. It's intriguing to see what you can do and how you can do it. Chip does a really nice job of looking at what happens in certain situations and seeing how we can take advantage of that."
Celek has developed into one of the better run-blocking tight ends in the league. But he's also a tough-to-bring-down receiving threat who has caught 55 or more passes in three of the last five seasons, including 76 in '09 and 62 in '11.
Ertz is matchup nightmare, who, like Celek, can line up wide, tight or in the slot.
"Zach creates a dilemma for defenses," Williams said. "Who do you assign to him? When we put two tight ends out there and you're in nickel, you got a little, bitty guy covering him. I always tell him, when you got those little guys covering you, make sure to take advantage of them.
"It's a fun problem to deal with. How do you get him in space? How do you get him on defenders who are lesser athletes? How do you get that done? If you're successful, you'll see big dividends."
Ertz has worked hard on improving his blocking, something he didn't have to do much of during his college career at Stanford.
"He's become a much better blocker," Celek said. "And I think he's going to continue to get better and better. It's a lot of technique stuff. Learning to block guys that are obviously a lot bigger than you.
"Then you kind of have to understand defensive schemes and where the guy's going to go, so you take the right footwork. Because if you don't take the right footwork, you're going to get beat. He's a smart kid. He's becoming more and more comfortable with it."
Last year, the Eagles actually were more effective running the ball out of "11" personnel (three wide receivers, one tight end) than they were out of "12." McCoy averaged 5.4 yards per carry out of three-wide-receiver sets, and only 4.4 out of two-tight end sets.
"I think I've made huge strides in the run-blocking game," Ertz said. "Especially the last couple of weeks in the preseason. Looking back at the film when we played the Jets [in the fourth preseason game] last year, I looked completely different than where I'm at now. Even the coaches are saying that. I'm just a lot more confident and am able to fire off instead of reacting to what the defense is doing. It's like night and day."
If they stay healthy, Ertz and Celek almost certainly figure to catch a lot more passes this year than they did last season. How many more? It wouldn't surprise me to see them combine for 125 receptions.
"We have to stay healthy, first and foremost," Ertz said. "And we have to develop that trust with the coaches and Nick.
"But we're going to get open. I think we've done that so far in the preseason and all throughout training camp."
"Just being more comfortable in the offense and being a year into it, hopefully we all will have more catches and the offense will be better as a whole," Celek said. "More rushing yards. More receiving yards."
And more distance in the rearview mirror between the Eagles and Jackson.
On Twitter: @Pdomo