Friday closed the book on a 16-year career that Manning spent with just one franchise, a rarity in today's professional sports.
And afterward, he reflected on the first time Manning revealed his character.
In a Twitter post Friday, Brady referenced Manning's two Super Bowl wins - both of which were over Brady and the Patriots.
"From the very first moment, I did it my way".
Then, four years later, Manning topped Brady again, becoming just the fifth player in National Football League history to win multiple Super Bowl MVP awards.
"Undoubtedly I would've made the fans, the media and even the front office more comfortable if I was a more rah-rah guy". Ultimately I choose to believe that my team-mates and the fans learned to appreciate that. "What they got was pure unadulterated Eli".
He will also be made a part of the Giants' ring of honor.
Eli Manning's highest-paid season was 2015, when he took home about $37 million, most of which was in a $31 million re-signing bonus.
Eli got wind of Brady's tweet and responded in his typical fashion, saying, "I've been around Tom". But more importantly, he went 8-4 in the playoffs and 2-0 in the Super Bowl.
"I don't think I need to make public comments for my family to know how I think about them", he said, "but Abby, and to Ava and Lucy and Caroline and Charlie, you are my rock".
Manning was told about Brady's remarks during the press conference and said: "We joke about it, but it's not really amusing to him". "But it's not real amusing to him".
Beyond the gridiron, Manning's work with his Tackle Kids Cancer initiative has raised $700,000 through Eli's Challenge, including an additional $250,000 in support past year.