MIAMI — The text that changed the franchise came in so early on Oct. 30, 2017, that Kyle Shanahan wasn’t even at his office yet, and, of course, he usually gets there before sunrise.



“I was on my way in,” Shanahan recalled Tuesday. Awake. Heading to Levi’s Stadium in the darkness. With his entire 49ers foundation about to change.



The 49ers were 0-8 at the time, and Shanahan wasn’t in the greatest mood. He was in his first year as the 49ers coach; he and John Lynch had a long-term plan about rebuilding the franchise, and they knew their roster wasn’t even close to competing for the playoffs. And the team was proving that every week, against every opponent, which wasn’t the most enjoyable feeling in the world.



But then the text came in. Shanahan checked his phone: New England Patriots coach Bill Belichick was reaching out.



“It was like 5 in the morning,” Shanahan remembered. “And we had...