Who’s more responsible for the New England Patriots’ dynasty: Tom Brady or Bill Belichick?

It’s a question that’s been tossed around for years, and the debate gained steam in recent months amid reports of tension in Foxboro. Ian O’Connor’s upcoming book, “Belichick: The Making of the Greatest Football Coach of All Time,” will stoke the fire even more, as it features several juicy nuggets about the longstanding relationship between the Patriots’ beloved quarterback and their genius coach.

ESPN.com published an article Wednesday detailing some of the notable material in O’Connor’s book, which hits shelves next week, and it’s clear Brady and Belichick haven’t always seen eye to eye. For one, Brady’s camp long has felt like Belichick will push out the QB before he’s ready to retire, especially since the Patriots drafted Jimmy Garoppolo in the second round in 2014.

From ESPN.com’s article about O’Connor’s book:

Brady started worrying for his job almost immediately after Belichick cited his age and contract status — and the coach’s desire to be “early rather than late at that position” — when the Patriots drafted Garoppolo in 2014. One New England assistant said the general feeling among staff members around that time wasn’t that Belichick’s system could make Super Bowl quarterbacks out of all 32 NFL starters. “But if you gave us any of the top 15, we could do it,” the assistant said. “I don’t think the coaches view Tom as special as everyone else in football does. Mr. Kraft thinks Tom is the greatest gift ever, but the coaches don’t.”

The Patriots ultimately traded Garoppolo to the San Francisco 49ers last October, and Brady, now 41, reworked his contract over the offseason and reinforced his desire to play into his mid-40s.

But the unnamed Patriots assistant’s assertion that New England would have had similar success over the years with one of several other starting NFL quarterbacks sure is bold. It directly attacks Brady’s status as arguably the greatest QB in league history, and it serves as additional evidence that things really haven’t been all sunshine and rainbows in New England despite the Patriots’ continued success.