Patrick Mahomes, J.J. Watt, and Derek Jeter took time to congratulate Brady on his storied career -- expressing how much it meant to watch him play in the NFL.

Of course, Mahomes and Brady have had their fair share of battles over the years -- they played against each other in an AFC Championship Game and in Super Bowl LV.

Brady announced his retirement with a video on social media ... and once the Kansas City Chiefs' star quarterback got wind of the news, he tweeted three GOAT emojis at TB12.

Watt -- who announced his own retirement earlier this season -- spoke about how special it was to compete against Tom, calling him the unquestioned GOAT.

"Greatest of All Time," Watt tweeted. "No question, no debate. It’s been an honor and a privilege. PS - The newly retired group meets on the golf course every morning at 10am."

"Drinks are on the new guy, so bring your wallet."

Ex-NY Yankees captain Derek Jeter -- one of the greatest performers in MLB postseason history -- congratulated TB for all his accomplishments, saying, "it was fun to watch."

Broncos quarterback, Russell Wilson -- who Brady defeated in Super Bowl XLIX as a member of the Seahawks -- wrote on Twitter, "Congrats Tom. Salute to the Greatest."

Brady's retirement was a surprise to some ... although he announced he was retiring on the same date last year. This time, it appears the G.O.A.T. is hanging up his cleats for good.