LeBron James and Serena Williams have led tributes to Tom Brady in a stunning video reflecting on the legendary quarterback's career ahead of the Super Bowl.

Brady will be a spectator today and the seven-time champion will watch on knowing that he will no longer have a chance to compete in America's ultimate game after announcing his retirement at the age of 45 last week. 

Michael Phelps and Jordan Spieth also appear in the video with James and Williams to reflect on what Brady means to them.

It is The King whose tribute is the most powerful - his words coming days after the 38-year-old Lakers star became the NBA's all-time leading points scorer.

'We all heard that Father Time is undefeated,' James says. 'But while we are in the position that we are in, we are trying to slow it down because we have so much more to give to the sport.

'What we're chasing isn't just about being great. What we are chasing is about being the greatest of all time. To see Tom playing some of the best football anybody has ever played, at any age, is very inspiring. Tom Brady's legacy is one word: champion.' 

Williams, who announced her retirement from tennis before the 2022 US Open with 23 Grand Slam titles to her name, said: 'Time plays a huge role for an athlete. 

'Time can run out and it can effect whether an athlete is able to win that one game that they needed.

'The hardest part about sustaining greatness over a period of time is people wanting to catch up with you. You have to do things better - you are having to surprise people. You have to, every year, go out and do something different because they are coming for me.

'The very first Super Bowl Brady played, he wasn't intimidated by the occasion. He kind of looked it right in the eye and said "I am going to take you down, I don't care who I am playing against, I don't care what statistics say, I am going to do this"'.

Phelps, a 23-time Olympic gold medalist, said: 'I am not afraid to dream as big as I can. I am not afraid to think of things that nobody thinks of.

I never back down form a challenge. You watch Tom Brady - he never backs down from a challenge.'

Three-time golf major winner Jordan Spieth said: 'What I think makes Tom Brady great is his mental ability to slow time down and make decisions so fast.

'Tom Brady's greatest legacy will be certainly the duration of greatness he has displayed throughout his career - I mean, it is just insane.'

Brady announced his retirement on February 1 in a video he posted to social media.

'I'm retiring, for good. I know the process was a pretty big deal last time so when I woke up this morning I figured I'd just press record and let you guys know first.

'It won't be long-winded. You only get one super emotional retirement essay and I used mine up last year, so... really, thank you guys so much to every single one of you for supporting me.

'My family, my friends, my teammates, my competitors. I could go over forever, there's too many. Thank you guys for allowing me to live my absolute dream. I wouldn't change a thing. Love you all.' 

Meanwhile. the Kansas City Chiefs play the Philadelphia Eagles later on Sunday in the Super Bowl in Phoenix, Arizona.