Brady, 43, is working primarily with defensive coordinator Jonathan Gannon and his staff, offering perspective as an offensive coach on how he would attack the Eagles' defense, a source said.
Having coached in Indianapolis alongside coach Nick Sirianni for three seasons, Brady would have intimate knowledge of some of the offensive principles the Eagles employ, seeing as Sirianni's time in Indianapolis played a big role in shaping the Eagles' coach.
The Eagles and Colts played last week, with Philadelphia edging Indianapolis 17-16. Brady came to Philadelphia last week to discuss a potential role with the team, according to a league source. The Eagles waited until early this week to hire him, given the sensitivity around the game, the source added.
Brady coached the quarterbacks when Sirianni was the Colts' offensive coordinator 2018-20. He replaced Sirianni as offensive coordinator when Sirianni was hired to be head coach of the Eagles in 2021.
Brady was fired by the Colts after the team's second straight loss in which its offense scored just a single touchdown. At the time, coach Frank Reich -- who was fired two weeks later -- described the move as "an incredibly hard decision but one I felt needed to be made in the best interest of the team."
It was an emotional return to Indianapolis last week for Sirianni, who counts Reich among his primary mentors. Late in the game, with the win cemented, Sirianni approached the stands near the visitors sideline and screamed into the crowd: "That s--- was for Frank Reich."
He worked to collect himself as he walked through the tunnel, but when he hugged Eagles general manager Howie Roseman at the locker room entrance, he welled up, wiping tears from his eyes as he went to address the team.
"I'm emotional because I love Frank Reich. I really do," said Sirianni, who served as Reich's offensive coordinator in Indianapolis from 2018 to 2020. "He's one of the best damn football coaches I've ever been around. I was hoping that he and I would be able to coach against each other this game. He is one of my biggest mentors.