Having locked up the No. 1 seed in the AFC playoffs, the Patriots played it safe with some of their injured players, most of whom would have been in action if this was the playoffs. They also made it a half-day's work for other top personnel, a group including quarterback Tom Brady, cornerback Darrelle Revis, linebacker Jamie Collins and safety Devin McCourty.
Then there was the decision that stood out above all else -- to make tight end Rob Gronkowski inactive despite his healthy status, the only player not on the team's lengthy injury report to sit out.
That one spoke volumes.
We've touted Gronkowski's value to the Patriots all season, pointing to him not just as the team's MVP, but also as a player worthy of league-wide MVP consideration. It goes well beyond his 82 catches for 1,124 yards and 12 touchdowns; more so it is how his sheer presence has consistently opened opportunities for others to make plays, such as four defenders gravitating toward him in the end zone to create favorable matchups elsewhere.
Now we know that Belichick sees it very much the same way, because in some ways sitting Gronkowski was an un-Belichickian-type move by putting one player above the rest of the team.
Gronkowski, of course, is worthy of such consideration and no one in the Patriots' locker room seemed offended.
"He's obviously very valuable, one of the biggest parts that makes the offense go," fellow tight end Steve Maneri said. "I think the tight ends looked at it on the whole as an opportunity to see what we could do, because when 87 is in there, he's 'The Guy.'"
We might propose expanding that to "The Guy Who Changes Everything."
This is obvious by now when considering what has unfolded the past three years in the playoffs. In the 2011 season, a hobbled Gronkowski gutted through a serious ankle injury in the Super Bowl, but he wasn't himself and the offense sputtered. Without Gronkowski the past two postseasons -- first because of a broken forearm in 2012 and the second due to a torn ACL in 2013 -- the Patriots again faltered.
So one could understand why Belichick didn't want to take any chances in Sunday's regular-season finale, and why Brady seemed to go out of his way to point out that the return of Gronkowski and fellow receiver Julian Edelman (out the past two games with a concussion) would alter the outlook compared to what we saw Sunday.
Nine-year Bills defensive tackle Kyle Williams, who knows as well as anyone what it's like to face the Patriots, essentially said the same thing himself.
"I think any time you have a player that is probably the best player at his position in the league, that obviously opens up a lot of avenues for them offensively. He's a great weapon for them and Tom to have," Williams said after Sunday's game, the first time he has been part of a team that defeated the Patriots on the road.
"He can catch the underneath balls but also take it up the field. He blocks well. They move him around quite a bit. They do a lot of things well with him, schematics wise, where you really have to be on top of it."
The Bills didn't have to deal with that Sunday, yet when Williams was informed that some in New England might have concern with the team's offense based on struggles in recent weeks, he didn't share the sentiment.
"What they do, and their scheme, they're really hard to defend with Edelman and Gronkowski and what they bring to the table, and the way Tom controls everything at the line of scrimmage," he said. "He can get them in and out of good plays and where they can be successful. As long as they have those guys, especially No. 12 at the helm, I think they're going to be OK."
As for Gronkowski, perhaps the statistic that reflects his value more than any other is the team's won-loss record based on his presence.
When he was still working himself into top form coming back from the ACL injury through the first four games of the season, averaging just shy of 35 snaps per game, the Patriots were 2-2 and in search of an offensive identity.
When Gronkowski upped his workload considerably in Week 5 and averaged 63 snaps per game between that point and Week 16, the Patriots were 10-1 and defenses seemed to devote more attention to him with each passing week.
So it wasn't any great shock that the Patriots' offense once again looked out of sorts in the first half Sunday when Brady was still leading the charge. Without Gronkowski, everything looks different, and that's why Belichick took the extreme step of making sure he'd be there when it counts, in the playoffs.
"He's a huge part of their offense, obviously their go-to guy, their playmaker," agreed Bills linebacker Nigel Bradham. "He and Brady have chemistry and what he's done in the league so far, he's changed the game with tight ends."