The 30-year-old tight end forged what the team described as a "special legacy" in an eight-year spell in Pennsylvania that included winning Super Bowl LII.
Ertz joined the Cardinals in exchange for a fifth-round draft pick in 2022 and rookie cornerback Tay Gowan, it was confirmed on Friday.
Ertz's defining moment for the Eagles came in the Super Bowl defeat of the New England Patriots three years ago, his 11-yard catch and drive for the end zone late in the fourth quarter helping to secure a 41-33 victory.
A second-round pick in 2013, Ertz made an NFL-record 116 receptions in 2018 and is second only to Harold Carmichael for catches in Eagles history, making 579 in the regular season and 33 in the playoffs.
He signed off in style on Thursday, scoring a touchdown in the 28-22 loss to the Tampa Bay Buccaneers at Lincoln Financial Field in what proved to be his final appearance for the franchise.
"Zach Ertz built a special legacy in Philadelphia," said chairman and CEO Jeffrey Lurie. "Talented, tough, and passionate, he helped to establish our team's culture and played a vital role in our success over the years.
"Zach created so many memories that will live on forever, from setting numerous franchise and league records, to reaching across the end zone for the game-winning touchdown in our first-ever Super Bowl Championship. He will always be a member of the Eagles family, not only because of what he accomplished on the field, but also because of the wonderful person, dedicated leader, and exemplary role model that he was for nine seasons in Philadelphia. We wish Zach and [wife] Julie nothing but the best."
The Cardinals, top of the NFC West after a 5-0 start, welcomed Ertz as a "talented replacement" for Maxx Williams, who is out for the rest of the season with a knee injury.
Tight end Ertz did not play against the New York Giants in Week 17 as the Eagles clinched the NFC East, sitting out the game due to rib and back injuries.
Along with offensive lineman Lane Johnson – who has not featured since Week 14 due to an ankle issue – Ertz was listed on the team's latest injury report on Friday as questionable.
"He is still not cleared for any contact," Philadelphia head coach Doug Pederson said of Ertz prior to Friday's practice session.
"He will work a little on the side, like he's done this week. We're waiting on a few doctor results tomorrow [Saturday]. If things go favourably, he'll play and if they don't, he won't."
As for Johnson, the Eagles' selection with the fourth pick in the 2013 draft, the two-time Pro Bowl tackle was limited in practice on Wednesday and Thursday but did not participate at all on Friday.
Wide receiver Agholor has been ruled out contention due to a knee injury, scuppering his hopes of facing the Seahawks at Lincoln Financial Field.
While his absence will be a blow to a depleted offense already without fellow receivers Alshon Jeffery and DeSean Jackson, there was some good news for the team concerning Miles Sanders.
The rookie running back hurt his ankle during the 34-17 triumph over the Giants but was a full participant in practice on Friday.
At 7-0 after routing the Texans on Sunday, the Cardinals are the NFL's lone unbeaten team and are off to their best start since 1974.
For a team that have not won more than eight games in a season since their last trip to the playoffs in 2015, the Cardinals are brimming with confidence heading into a Thursday game against the 6-1 Green Bay Packers.
While quarterback Kyler Murray said he "wasn't too concerned" when the Cardinals came up empty on their first three offensive possessions – which included Arizona star being caught in the end zone for a safety – he noted they cannot make a habit of it.
"I don't know why, maybe came out a little lax," Murray told a news conference. "I just know we've got to be better, because you get beat if you come out too slow. Sometimes you may not be able to catch up.
"So for us, I know we're better than what we put out there today. We kind of clicked, for the most part, during the middle of game but [Houston] got after us today. I don't want to take anything away from them. Obviously we won by large lead but for the most part offensively, I think, we can be a lot better."
Murray followed up that safety by leading a 14-play touchdown drive that got the Cardinals on the scoreboard and they did not look back from there, leading 17-5 at the half before tacking on two more TDs after the interval.
Arizona's slow start may also have been attributable to head coach Kliff Kingsbury's return to the sidelines after missing the previous game against the Cleveland Browns following a positive COVID-19 test.
While the Cardinals had no trouble in that 37-14 blowout, Kingsbury said it took him a while to find his rhythm against the Texans after missing the entire week of practice before he was cleared to coach in the game on Sunday.
"I felt a little disconnected," he said. "I didn't feel as into the game as I usually am, just showing up on game day, but the players are awesome, great energy and made me feel very welcome to be back."
Murray said he did not pick up on his coach's discomfort but noted that it did not seem to be detrimental.
"I'm sure he probably felt a little bit off, but we put up 31 today, defence played great," Murray said. "It was a great team win so for him to feel awkward or whatever and then we still put up 31 is a good job and you know we've got to keep it going because the Packers are coming in as a great team."
In his first game with the Cardinals after being acquired from the Philadelphia Eagles, Zach Ertz caught a 47-yard touchdown from Murray – his longest TD of his career.
Ertz also became the first player in NFL history with a receiving touchdown in consecutive weeks for two different teams.
