The agreement? To let Brady leave the team if he felt the relationship with Bill Belichick had become too strained.
In his new book "The Dynasty," author Jeff Benedict chronicles the machinations in early 2018 when Brady - worn out by the dynamics of the 2017 season - made it clear he wanted to leave.
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And that Kraft, after ruminating on the request, agreed to let Brady do so.
"Tommy, if you want to go, you can go," Kraft told Brady on a phone call during that time.
Benedict's book goes deep on the Patriots dynasty. While it's very Kraft-centric in the early stages, detailing the owner's early life and how he positioned himself to buy the team and turn it into what it's become, the access Benedict got to the principals is what makes it a terrific read.
The friction between Brady and Belichick that simmered throughout 2017 after the Patriots historic Super Bowl win over Atlanta came to a head in the weeks following the Super Bowl loss.
Kraft's paramount concern (after the Super Bowl) was the dynamic between Beichick and Brady. Belichick's decision to banish (Brady's body coach and TB12 business partner, Alex) Guerrero from the sideline and the team plane in the middle of the 2017 season had been a tipping point. Kraft knew that Belichick's methods were grinding on Brady. He also knew that Belichick was tired of the exceptions that Kraft felt were necessary to accommodate a transcendent star. The differences of opinion between Brady and Belichick were more pronounced than ever. Kraft wanted to clear the air.
Benedict went on to detail a meeting between Kraft and Belichick at Davio's Patriot Place. The conversation was "productive" and the two men set up a meeting with Brady at Kraft's home.
Kraft ushered them into his living room. Belichick took a seat on a chair to Kraft's right and Brady sat on a couch to Kraft's left. Hoping to facilitate some constructive dialogue, Kraft told them how important they both were to him. Belichick was diplomatic. Brady was respectful. But the distance between them was obvious.
Soon after, Benedict writes, Kraft summoned Brady and his wife Gisele Bündchen to his home for a discussion. Bündchen took up for Brady. After pointing out how much Brady had done for the organization:
She also pointed out how ridiculous it was that after all these years, Belichick still treated Brady like "f****** Johnny Foxboro." It was bad enough to never voice approval. It was bullshit to still be dressing down the most accomplished quarterback in league history during team meetings and treating his personal trainer and best friend like some kind of outcast.
When the conversation shifted to the future, Brady and Bündchen indicated it was time for them to make some changes that were in the best interest of their family. Among other things, they were contemplating a change of scenery.
Kraft wasn't surprised by their feelings toward Belichick. He hadn't, however, expected to hear that Brady and Bündchen wanted to leave New England.
Benedict then revealed the agreement Kraft and Brady made in 2010 over lunch on the Cape during the most arduous negotiations of Brady's career to that point.
That year, Brady feared that Belichick might soon move on from him. He re-signed with the Patriots only after Kraft promised he'd protect Brady by stepping in and essentially allowing him to leave on his own terms if Belichick ever decided to trade him. Their unwritted understanding had been the key to keeping Brady in New England for so much longer than any other player who'd played under Belichick.
But in this instance, Kraft wasn't inclined to let Brady walk away from the Patriots and play for another team. Belichick might have preferred (Jimmy) Garoppolo at one time but Garoppolo was gone. Belichick was counting on Brady's being the Patriots quarterback in 2018. So was Kraft. He explained that to Brady and Bündchen.
The conversation was a difficult one and it ended without resolution.
At this point, Brady's dissatisfaction with Belichick was morphing into an irritation with Kraft for what Brady perceived as Kraft going back on his word.
There was another meeting with Kraft, Brady and Bündchen. Kraft said he'd lobby Belichick to lighten up a little but that Kraft wasn't going to let Brady out of his contract.
When Kraft made his position clear, it was as if he had hit the lowest key on a piano. Silence filled his living room. On that note, Brady and Bündchen left without saying anything more.
Later that night, Kraft called back and told Brady he could go if he wanted.
The next day, Kraft called Brady again, according to Benedict.
"Look, I know I told you that you could leave," Kraft said. "But I hope you don't."
"I'm not," said Brady.
Brady had been talking with Bündchen about playing for two more years and remaining in New England.
"I don't want to go," Brady told Kraft. "I'll work it out on my end."
Working it out meant that Brady would be spending more time with his family in the 2018 offseason and not at OTAs.
Meanwhile, Benedict writes, Belichick "decided to move on from (Rob) Gronkowski" as Kraft and Brady were hashing things out. Gronkowski was told on April 22nd he'd been traded. "Pissed," Benedict writes, "he notified the Patriots that he wasn't going to Detroit. Instead he would retire. He had one other message for the team - Brady was the only quarterback he'd play with."
The relationship didn't mend itself magically after that. The incentive-laden contract bump Brady was given later in the summer prior to the year was another source of irritation. A source told me that summer that the contract was akin to refusing to take the thorn out of a lion's paw.
But by the time the season started, Belichick and Brady pocketed their grievances and got along better than they had in years, sources told me at the time.
Everything wasn't fixed forever - the two men were at cross-purposes in that Belichick wanted to build for the future and a 40-plus quarterback didn't fit that bill - but they got along well enough to go 11-5 in 2018, and then rampage through the playoffs to another Super Bowl.