Ertz told reporters Thursday that contract talks with the Eagles have been "frustrating at times" and "difficult," but he hopes to remain with the team for a long time.
"I don't know for sure if that feeling is mutual," Ertz said, adding he will play the 2020 season "as if this is my last year."
The Eagles exercised their 2021 option worth $8.25 million on Ertz's contract in March.
NFL Network's Ian Rapoport reported on Sept. 3 that talks between Ertz and the Eagles "came to an abrupt halt" because Philadelphia's backloaded proposal included less guaranteed money than a previous offer made last November.
Recent extensions signed by George Kittle of the San Francisco 49ers (five years, $75 million) and Travis Kelce of the Kansas City Chiefs (four years, $57.25 million) set new benchmarks for tight ends.
Per Jeff McLane of the Philadelphia Inquirer, Ertz "clearly wants to move now" on a deal after those extensions, but noted the Eagles also have Dallas Goedert on the roster.
Goedert, a second-round pick in 2018, had a breakout season last year with 607 receiving yards and five touchdowns on 58 receptions.
Ertz's five-year, $42.5 million deal signed in 2016 made him the fourth-highest paid tight end by guaranteed money and average annual salary.
The Eagles selected Ertz in the second round of the 2013 NFL draft out of Stanford. He has had at least 74 receptions and 816 yards in each of the past five seasons. The 29-year-old has been named to the Pro Bowl every year since 2017.