"I think Zach can have a huge role," coach Chip Kelly said last week.
An Ertz jump probably would have come in his sophomore season even if Jackson had stayed. He has the look of a "future Pro Bowler" - the first-round grade the Eagles gave him last year - and over the last decade that caliber of tight end has seen his production spike from Year 1 to Year 2.
In the previous 10 seasons, 19 tight ends were selected to the Pro Bowl. The 19 players, as a whole, averaged 30 catches for 334 yards and three touchdowns in their rookie years. A year later, they averaged 56 catches for 649 yards and five touchdowns.
The rookie-to-second-season jump was even greater for two future Hall of Fame tight ends and two younger tight ends with Hall of Fame talent.
The Chargers' Antonio Gates went from 24 catches for 389 yards and two touchdowns as a rookie to 81 catches for 964 yards and 13 touchdowns. Jason Witten of the Cowboys jumped from 35-347-1 to 87-980-6.
The Patriots' Rob Gronkowski and the Saints' Jimmy Graham soared from 42-546-10 and 31-356-5, respectively, in 2010 to 90-1,327-17 and 99-1,310-11 in 2011.
Ertz, 23, obviously has a way to go before he can be mentioned in that company. But he caught 36 passes for 469 yards and four scores despite playing only 41 percent of the Eagles' offensive snaps last season - numbers as good as any rookie tight end in 2013.
If Ertz can improve his blocking, he'll see more time than even the loss of Jackson and his own natural progression would warrant.
"As for comparing myself to other tight ends - I want to be one of the best in the game, and I've got to be on the field more, obviously, to do that," Ertz said recently. "And that's what I'm really working towards this offseason."
The Eagles expect as much.
Ertz has become the team's poster boy for its best-available-player draft philosophy. The Eagles didn't exactly need a tight end with Brent Celek and James Casey already on the roster last year. But when Ertz was available with the third pick of the second round, Kelly and general manager Howie Roseman pounced.
The Eagles considered Ertz essentially another first-round pick after tackle Lane Johnson, but it took a while for the Stanford product to see extended time. He played only 24 percent of the snaps in the first three games, but 47 percent over the next 11.
Ertz pulled in 28 passes for 325 yards and four scores during that 11-game span. His blocking improved, as well, but not enough to be on the field late in the season whenever the Eagles went with two tight ends in run sets.
Celek and Casey got the nod, and Ertz's snaps decreased in the final two regular-season games.
"I've tried to get stronger this offseason," Ertz said. "Obviously, the No. 1 goal is to be the complete tight end."
Ertz missed a large number of practices last spring because of Stanford's late graduation. He's had this entire offseason to focus on the coming season and has apparently been diligent in his preparation.
He said he still weighs 250 pounds at 6-foot-5, but his body fat has dropped considerably.
"The encouraging thing for Zach is when you see him in the building you can see how much broader he's gotten, how much he's worked on his body," Roseman said. "We talk about it all the time, missing that month based on his school schedule, and that's hard."
Ertz actually went back to school after the season. He worked out in Palo Alto, Calif., with other Stanford alumni, including Colts quarterback Andrew Luck, from whom Ertz caught many passes.
They worked the entire route tree, and Ertz lined up all over the place, as he did in college. The Eagles had him split wide often last training camp, but he ended up running most of his routes from inside or out of the slot.
"He's got the ability to be a flexed-out guy," Roseman said. "He can play with his hand down. He can play in the slot. He can line up outside. He's a hard guy to cover because he's got really good feet, [and] obviously he's big."
The Eagles found they didn't need to split him wide to create mismatches. By the end of the season, opposing defensive coordinators were using more safeties and slot cornerbacks than linebackers to cover Ertz.
While that gave defenses the chance to cover Ertz downfield, he was often able to outmuscle defenders for the ball. The mismatch was also exploited in the run game.
Improved blocking will boost his playing time, but the Eagles drafted Ertz for his pass catching. And if he follows the same curve as the game's best from the last decade, he'll play as often as Jackson or any starting receiver.
Ertz hasn't shied away from those comparisons.
"Nobody's going to be harder on me than myself," he said. "That's how I think a lot of the very successful athletes have been in the past. . . . I think to be one of the best you have to put that kind of pressure on yourself."
Tight End Spike
Four active Hall of Fame-caliber tight ends saw a significant jump in production in their second year in the league. Could the Eagles' Zach Ertz see a similar spike in 2014?
Antonio Gates Rec. Yards TD
Rookie year, 2003 24 389 2
Second year, 2004 81 964 13
Jimmy Graham Rec. Yards TD
Rookie year, 2010 31 356 5
Second year, 2011 99 1,310 11
Rob Gronkowski Rec. Yards TD
Rookie year, 2010 42 546 10
Second year, 2011 90 1,327 17
Jason Witten Rec. Yards TD
Rookie year, 2003 35 347 1
Second year, 2004 87 980 6