Let's look at Graham first, though, just to establish a baseline. Standing 6-foot-7 and weighing 265 pounds, 27 years old, he has become the Platonic ideal of the tight end position in the modern NFL. Over the last three seasons, Graham has caught 270 passes - 36 of them for touchdowns - and averaged nearly 13 yards per reception. Even as a rookie, in 2010, he had 31 catches and five touchdowns despite lining up for just 238 snaps. He runs like a sprinter and is as physical as a Caterpillar bulldozer.
"He's a beast," said Ertz, who himself is 6-5 and 250. "He's probably the best pass-catching tight end, if not the best pass-catching player, in the game right now. He's so big and athletic. He can do anything on the field."
All of that may be true. It probably is true. But Graham also plays in an offense that's built around Drew Brees, who throws a seam route - the kind of pass pattern at which tight ends such as Graham and Ertz excel - as well as any quarterback in the NFL. And the Saints throw the ball a lot. They threw it 661 times in Graham's rookie season, which meant he wasn't required to run-block as much as Ertz has been in this year's Eagles' offense.
In 2010, in fact, Graham run-blocked on just 66 plays, according to the scouting and statistical firm Pro Football Focus. Ertz run-blocked 181 times this season, and remember: He isn't even the Eagles' primary run-blocking tight end. Brent Celek and James Casey handle those duties with more relative frequency.
So the fact that Ertz still had 36 receptions - more than Celek (32) and Casey (3) combined - and averaged 13 yards per catch offers an indication of how well-rounded he is and may yet become.
"I want to make Pro Bowls, do all the great things," Ertz said. "I think I can contribute to the team in a multitude of ways. As the season progressed, I picked up more and more each week. Now I've kind of established my role, and I think I'm playing at a pretty high level right now."
One of the interesting aspects of Ertz's transition into the NFL from college is that he stepped into a situation with the Eagles that was all but identical to the one he experienced at Stanford.
There, he had shared playing time with two other tight ends bound for the pros: Coby Fleener, now with the Indianapolis Colts, and Levine Toilolo, now with the Atlanta Falcons. When they selected Ertz in the second round of last year's draft, the Eagles already had a longtime starter in Celek and had recently signed Casey as a free agent. It might have been natural for Ertz to wonder when he'd see the field. He didn't.
"I was really happy about it," he said. "Chip was such a great offensive mind that he's going to put his players in positions to be successful, whether that's Brent or James or any of the other players on this offense. He's done a very good job with that."
It stands to reason Kelly will get better at it in the future, and that Ertz will flourish as a result. Everyone will be keeping an eye on Jimmy Graham on Saturday night at Lincoln Financial Field, and everyone should. But the Eagles have a Chip Kelly guy at tight end who's worth watching, too, now and for a long time to come.