Brent Celek is the starter and that's not expected to change this year. In a way, Celek and Zach Ertz are playing two different positions. Kelly explained that Ertz [as well as James Casey] is being used as a "move" tight end in this offense. That is similar to the way Aaron Hernandez was deployed in New England -- as more of a "Joker" that lines up in various spots and is used primarily as a pass-catcher. Celek is more of the traditional "in-line" tight end where blocking is a bigger priority.
Celek could very well end up with more snaps, but that doesn't mean that Ertz won't be featured prominently.
Ertz averaged 2.8-32-.56 over the final nine games of the season (including the Eagles' sole playoff game) and that included two goose eggs in Week 10 and Week 14. That equates to 6.6 fantasy points per game, which is what Martellus Bennett averaged as the #10 TE in fantasy football. With Jason Avant and DeSean Jackson gone, Ertz could play a lot in the slot, though the arrival of WR Jordan Matthews may limit Ertz’s snaps there.