For two decades, Tom Brady and Bill Belichick formed the deadliest, most terrifying duo in the whole National Football League. They were a dynasty of their own, perennial contenders, and perhaps the greatest coach-quarterback duo of all time.

That's why it was kind of shocking to see Brady leave Foxboro after 20 years with the organization. He reportedly felt mistreated by the coach and had been thinking of leaving for some time.

Recently, Brady's personal trainer and lifelong friend Alex Guerrero, shed more light on the reasons why Brady wanted to leave the New England Patriots, citing that Belichick treated him like a 20-year-old.

Tom Brady's Trainer Says Bill Belichick Treated Him Like A 20-Year-Old

“The interesting thing I think there — and this is just me, an outsider looking in — it was like Bill never really . . . I think his emotions or feelings never evolved with age,” Guerrero told the Boston Herald.

“I think in time, with Tom, as Tom got into his late 30s or early 40s, I think Bill was still trying to treat him like that 20-year-old kid that he drafted. And all the players, I think, realized Tom was different. He’s older, so he should be treated differently. And all the players, none of them would have cared that he was treated differently. I think that was such a Bill thing. He never evolved. So you can’t treat someone who’s in his 40s like they’re 20. It doesn’t work," he concluded.

Brady's Wife Also Called Out Belichick

This isn't the first time that someone close to Brady says something like that. Months ago, his wife Gisele Bundchen also said that Belichick treated him like he was just another player, which didn't sit well with his star quarterback:

"She also pointed out how ridiculous it was that after all these years, Belichick still treated Brady like “f****** Johnny Foxboro," our previous report stated.

We get it, Bill. That's your philosophy and you don't want to play favorites. Everything's earned, not given. But C'mon, man. We're talking about Tom freaking Brady right here. He's earned his stripes as much as you, if not more.