It may have been more than a week since Tom Brady officially announced his retirement from football, but his shocking decision is still a topic of discussion in the NFL. And you can't blame anyone who keeps talking about it.

Brady leaves behind one of the greatest legacies in sports, with a 22-year career in which he broke multiple records, including the most Super Bowl rings won by any player or franchise.

Nobody expected it when he entered the league with the New England Patriots, but Brady eventually made a strong case to be considered the GOAT. Joe Montana, who was also considered the best of all time before Brady arrived, has shared his opinion on this debate.

Joe Montana is full of praise for Brady but says it's hard to compare different eras

Far from being jealous of what Brady achieved during his time in Foxborough and his final years with the Tampa Bay Buccaneers, Montana showed a lot of respect for Brady and everything he achieved.

Tom’s had a tremendous career, played a long time, former San Francisco 49ers quarterback Joe Montana told NFL Network, as quoted by Clutchpoints“Definitely belongs up there in that spot.”

However, he also suggested that the GOAT debate is not that easy. Montana understands that the game has changed over the years, making it hard to determine who's the best of all time.

There’s just so hard to compare,” Montana said. “Go back and look at Otto Graham, who won, what 10 or 11 championships before there were Super Bowls. Watch him play and how do you compare him to that era where what did they to wide receivers back then, they’d grow you in jail for. It’s just hard to compare everybody. The game is different. The game changes. Tom’s had a career that will be tough to catch.”