Hall of fame signal-caller Joe Montana knows the difficulties of changing teams following a historic career with a single franchise, a transition New England Patriots quarterback Tom Brady could face this offseason.

"It's not easy to go to another team and get accepted, no matter how much success you've had and how many years you've played," Montana told NFL.com's Michael Silver. "They still want to see you come in and be the same player and be that loyal to them as you were to the other team you just left. So, it's not easy (for) guys looking at that change, especially at the quarterback position."

Montana won four Super Bowls over a 14-season tenure with the San Francisco 49ers before the team traded him to the Kansas City Chiefs in 1993. The two-time NFL MVP posted a 20-12 record in two seasons as the Chiefs' starter, leading Kansas City to the AFC Championship Game once.

Brady, who will be 43 years old when the 2020 season kicks off, is a free agent this offseason. The Patriots can't franchise tag him.

Asked if he had any advice for Brady regarding a potential departure from New England to sign with a different team, Montana offered the Patriots icon a warning.

"Don't - if you don't have to," he said. "It's a process to go through, and it takes time to get used to the team. I was fortunate because (former 49ers quarterbacks coach) Paul Hackett was there running the offense, and so I was pretty familiar with probably three-quarters of the offense going in. And, if they let (Brady) have his own offense (with a new team), yeah, that makes it a little bit easier.

"But still, the transition of moving ... I just can't see how they would let him leave there, myself."

Selected by the Patriots in the sixth round of the 2000 NFL Draft, Brady has won six Super Bowls and three league MVP awards while throwing for 74,571 yards and 541 touchdowns over 20 pro seasons.