The afterglow from the biggest comeback in Super Bowl history faded quickly for New England.
After storming back from a 28-3 third-quarter deficit to defeat Atlanta 34-28, the Patriots made some roster tweaks. Their two biggest moves were signing former Bills cornerback Stephon Gilmore to a five-year, $65 million contract, and trading a first-round draft pick to the Saints for receiver Brandin Cooks.
In the Thursday night season opener, Kansas City clobbered the Patriots 42-27, as Alex Smith passed for 368 yards and four touchdowns. Drew Brees carved up New England for 447 yards a week later. Then DeShaun Watson and Cam Newton joined the fun.
Cooks had a strong start, helping stretch the offense for Tom Brady. But Gilmore and the defense struggled. Four weeks in, the Patriots ranked dead last in the NFL in total defense and second-worst in points allowed.
"I was telling [Gilmore] to ignore the media," veteran Patriots safety Devin McCourty said. "You're a new guy, you signed a huge free agency deal. We go 2-2, we're giving up [32.0] points per game, what's new? He's new. Well, it's his fault.'
"I wanted him to know that wasn't the case in the locker room. Us as a whole, we had a lot of work to do."
After Week 4, New England turned things around, leading the NFL in scoring defense (14.0 points per game), with the Vikings second at 14.7, from that point on.
This was nothing new for coach Bill Belichick. His best teams always seem to improve defensively as the season progresses. This turnaround happened even with injuries forcing the Patriots to use a patchwork line.
"There's not a pure pass rusher on their defensive front, a guy you go, 'Wow, he can rush the quarterback,' " said Greg Cosell, an analyst for ESPN's "NFL Matchup."
But the Patriots still sacked Marcus Mariota eight times in the divisional playoffs.
The defense is filled with relative no-names, outside of Gilmore and Malcolm Butler at cornerback, McCourty at safety and linebacker James Harrison, who came over from Pittsburgh in December.
"I think Patrick Chung is a terrific player, but when you talk about the best safeties in the league, no one names Patrick Chung," Cosell said. "I think it's the way [Belichick] uses players situationally.
"I mean over the last five, six weeks, [linebacker] Marquis Flowers has become a critical piece of their sub-package defenses, and no one probably even knows who that is."
The Patriots acquired Flowers, 25, from the Bengals for a seventh-round draft pick toward the end of training camp. With playmakers like him, New England's defense has become stifling, though not dangerous. The Patriots have not forced a turnover in their past four games.
"What's our record?" McCourty asked the Boston Globe, knowing the answer was 4-0. "That's the only thing I go by."
McCourty, a two-time Pro Bowl player, is one of Belichick's all-time favorites, "right at the top of the list," the coach said this week. The Patriots picked McCourty in the first round (No. 27 overall) of the 2010 draft and struck gold again in the second round, grabbing tight end Rob Gronkowski (No. 42 overall).
With McCourty in Gilmore's ear, pumping him up, and the pass rush jelling, things started clicking for the Patriots, who are 13-1 in their past 14 games.
Cook had 1,082 receiving yards in the regular season and added 100 in the AFC Championship Game. After the Patriots scored their two fourth-quarter touchdowns that game, Jacksonville had one last chance and drove into New England territory.
On fourth-and-14, Blake Bortles threw a catchable 30-yard sideline pass to Dede Westbrook. But a defender made a spectacular play, soaring in the air for what seemed like an eternity before swatting the ball away with his right hand.
It was Gilmore, doing the exact thing the Patriots gave him all that money to do. He spent five seasons with the Bills without making the playoffs once.
"That's one of the reasons why I came here," Gilmore said, "to be able to compete for a championship."