Ertz, last year's second-round draft pick, strives to become a more complete tight end, with improving as a run blocker a focus. A natural mismatch with his athletic, 6-5, 250-pound frame, he hopes to reach the point at which he doesn't come off the field on certain plays. Ertz as a rookie caught 36 passes in the regular season - one more than the combination of Brent Celek (32) and James Casey (3) - but this coming campaign figures to see an even larger role in Kelly's system.
"I think I can make a big jump," said Ertz, who last season caught five touchdown passes, including the go-ahead, fourth-quarter score in the playoff loss to the Saints. "I mean, I'm not a predictions guy. At the end of the day, all I really care about are the wins. But at the beginning of the year, I kind of started off slow. As the season went on, I think the numbers and the plays started to pick up and hopefully it's more of the same."
Twenty-two of Ertz's receptions and all four of his four regular-season touchdowns came in the latter half of the season, when the Eagles went 7-1 and seized the NFC East title. The game began to slow down for Ertz, he said, after his first NFL touchdown in the Week 9 blowout of the Raiders, the day Nick Foles tossed a record-tying seven touchdowns.
Ertz, 23, has a good rapport with the Eagles' 25-year-old starting quarterback. The two Pac-12 products don't live far from one another, Ertz said, and hang out off the field. Ertz said he thinks their chemistry shows up on the field and added that he thinks "the sky's the limit for this offense as a whole."
He used that same phrase when discussing Foles, who's entering his first season as the Day 1 starter after tossing 27 touchdowns with just two interceptions in 2013. "What he did last year, 27-2, is kind of remarkable," Ertz said. "But I don't think he's satisfied. Those two interceptions I'm sure are still bugging him, even the one in the snow.
"We do have a lot of playmakers on this offense," Ertz added. "The ball's going to be spread around. I think that's what Nick does best, is find whoever's open and get him the ball. It doesn't matter who you are or how many years you've been here. He's going to find the open man."
Ertz, a California native, spent February to April back in Palo Alto, working out at Stanford with college teammates Andrew Luck and Coby Fleener, both with the Colts, and the Falcons' Levine Toilolo. Whereas last May he resorted to Skype sessions with Eagles assistant tight ends coach Justin Peelle, Ertz is pleased to be in Philly this spring refining his game alongside his teammates.
The situation he faced last year is one that new Eagles safety Ed Reynolds, the recent fifth-round draft pick out of Stanford, is going through now. Ertz was able to lend advice to his former and now current teammate, who won't rejoin the team until the second week of June. Stanford is one of a handful of schools that goes by the quarter system, and NFL rules prohibit draftees from participating in more than one mini-camp until after final exams.
Ertz said he and Reynolds were good friends in college and he's excited to have him in Philly, where they will face off in practice once again. Ertz called Reynolds "a complete safety."
"I mean, the more Stanford guys and the less Oregon guys here the better," Ertz quipped. "So now we have two against about 100, so it's a step in the right direction."
Learning behind Celek, who Pro Football Focus rated the NFL's second-best run-blocking tight end last season, Ertz is working on advancing his technique in the trenches. But meanwhile, he's still continuing a ritual he started last season. After practice each day, Ertz, veteran Jason Avant and Brad Smith would catch 50 balls from the JUGS machine. Although Avant is now with the Panthers, the custom lives on.
"Can't ever catch enough balls," Ertz said. "You've got to perfect your craft."
On Twitter: @jakemkaplan