ESPN's Adam Schefter first reported the Eagles' decision on Thursday.
Sirianni spent the past three seasons in Indianapolis, during which time the team twice finished in the top 10 in yards and points.
It's no coincidence the Eagles are looking to an offense-minded coach. Upon reporting the move, NFL Network's Ian Rapoport tweeted how Philadelphia's "focus was always on fixing the QB situation."
The quarterback position was a cause for concern in Philadelphia as starter Carson Wentz struggled with a career-low 57.4 percent completion rate and 6.0 yards per attempt. He also led the NFL with 15 interceptions despite playing just 12 games. He was benched for Jalen Hurts in December.
Cutting Wentz, who is signed through 2024, would force the Eagles to swallow over $59.2 million in dead-cap money, per Over the Cap. Despite his struggles, that seems hard to believe and puts Sirianni in a tough spot with regard to handling the quarterback position in 2020.
In addition, the team is over the cap by $51.6 million, so the Eagles likely won't be serious buyers on the free-agent market as they look to shed salary just to abide by the cap.
The Eagles also had an aging roster with numerous key players aged 30 or older, including defensive lineman Fletcher Cox, center Jason Kelce, tight end Zach Ertz and more.
Many of those players have starred in Philadelphia and were part of the team's epic Super Bowl LII run, but the Eagles may decide to turn over a new leaf and restock the roster with younger talent.
That would put the onus on Sirianni to help mold and teach the young talent as the Eagles look to return to the playoffs.
Philadelphia does hold seven draft picks, including the sixth overall selection. It has many options at the position, with two notable ones being upgrading at wideout or finding a standout defensive player.
Ultimately, the deck is stacked against Sirianni as he starts his Eagles tenure, but a blue-chip prospect is presumably on the way to help out.
Plus, the NFC East would appear winnable, especially with the 7-9 Washington Football Team taking home the title last year.