Tom Brady is shedding more light on his decision to leave the New England Patriots in a new documentary about the NFL dynasty.

The new 10-part Apple TV+ series, The Dynasty: New England Patriots, is set to premiere on Friday.

In the new series, The Athletic reports, Brady, 46, and several former Patriots players say that conditions under former head coach Bill Bilichick became “brutal,” ultimately playing a role in Brady’s decision to leave the franchise after 20 seasons.

“Me and coach Belichick, we did what we loved and competed for 20 years together,” Brady says in the upcoming documentary, according to The Athletic. “But I wasn’t going to sign another contract [in New England] even if I wanted to play until [I was] 50. Based on how things had gone, I wasn’t going to sign up for more of it.”

Throughout the series, the outlet reports that former players open up about their grievances with playing for Belichick, who left New England last month and has yet to be hired by a new team.

“It was brutal,” former Patriots wide receiver Matthew Slater reportedly says in the doc.

Former Patriots tight end Rob Gronkowski reportedly describes arriving to the Patriots’ practice facility and sitting in his car outside, not wanting to go in for practice. Wes Welker, another former Patriots wide receiver, compares Brady’s treatment by the team to an abused animal.

Tomy Brady and Bill Belichick.TIMOTHY A. CLARY/AFP VIA GETTY

The Athletic calls the documentary “the most comprehensive view yet” of how sour the relationship between Belichick and his former players, including Brady, had become near the end of his tenure with the team.

Brady had reportedly sought a two-year contract worth $50 million after the 2019-2020 season, which the Patriots were unwilling to offer. Instead, Brady became a free agent and joined the Tampa Bay Buccaneers for that exact price in March 2020.

The decorated quarterback promptly won his seventh overall Super Bowl title in his first season with the team, adding fuel to sports pundits’ debate over whether Brady, Belichick or both should receive the majority of credit for the Patriots’ dynasty.

Tom Brady. STREETER LECKA/GETTY

When Belichick left the Patriots last month, Brady said he was “incredibly grateful” for his time in New England with him, calling Belichick “the best coach in the history of the NFL.”

“I could never have been the player I was without you Coach Belichick,” Brady wrote in a tribute post on Instagram. “I am forever grateful.”

Brady retired from the NFL last February, thanking fans, teammates, coaches, and his family for “allowing me to live my absolute dream.”

“I wouldn’t change a thing,” he said.