FOXBOROUGH, Mass. — And now, for Bill Belichick, the hard part begins.

Preseason is over, NFL roster’s have to be down to 53 players by 6 p.m. Saturday. And Belichick has to tell 22 players by then that they won’t be with the New England Patriots.

“This is the toughest part of the job,” said Belichick after Thursday’s preseason finale, a 28-20 victory over the New York Giants. “We got to camp with 90 players and we go to 53 so we know that we’re going to have to tell 37 people that they can’t be on the team.

“That’s the math. It’s always hard when guys work hard, do everything you ask them to, train hard, put forth all the effort they can put forth and you still have to tell 37 guys that they can’t be part of the team this year. It’s always a tough thing.”

One round of cuts was made earlier in the week, to get the team down to 75 players. Thursday’s preseason finale was a last-call for players who may or may not be wearing a Patriots jersey in a couple of days. The Patriots released 10 players Friday, including tight ends Jake Ballard and Daniel Fells.

Much was made on Twitter Thursday night as to who was on the field (veterans like safety Adrian Wilson and Fells played well into the third quarter, Leon Washington retuned punts the entire game) and who wasn’t (20 of the probable 22 opening day starters sat, the lone exceptions being right guard Dan Connolly, who has missed most of preseason with an injury, and rookie wide receiver Kenbrell Thompkins, who hasn’t earned the right to sit out just yet).

But, as Belichick made clear, the only thing that matters now is how each player can help the Patriots in the regular season. “We just try to put everything together and make the best decisions we can for this 2013 football team.”

Those who did get into the game knew exactly what it meant.

Michael Buchanan is a rookie defensive end out of Illinois, selected in the seventh round with the 226th pick of last April’s draft. When picked, he was projected as a depth player, someone who might be able to fill a small role. Physically imposing at 6-foot-6, 255 pounds, he was — and is — by no means guaranteed a roster spot.

But he prepared for this game like he hadn’t before, studying the tendencies of all of the offensive tackles the Giants might throw at him. And he responded. Playing the entire game, he had four tackles, 2.5 sacks, three quarterback hits and a forced fumble.

Asked after the game if he had thought about what’s ahead, i.e., cutdown day, he said, “I think everyone thinks about it. Every game, you’ve got to take it as if it’s a cut game.”

That’s why he studied film so diligently this week.

“I did a lot more preparing and getting ready, so that was the most comfortable I’ve felt,” he said.

Buchanan feels he has made his case, even before his efforts Thursday night.

“I think I’ve made a lot of improvement,” he said. “I think I’ve got a good grasp of my job on this defense and what my role on this team may be. Technique-wise, I think I made a lot of improvement, but I still have a long way to go.”

And what could his role be?

“Whatever I’m asked to do,” he said, an answer that surely will make Belichick smile. “If it’s special teams, if it’s passing rushing, whatever they ask me to do, I’m prepared.”

Guys who didn’t play, like running back LeGarrette Blount, hope they’ve done enough to earn a spot. Blount is in a battle for one a running back slot, along with Washington and Brandon Bolden.

That he didn’t play, he said, shouldn’t be taken as a sign that he’s made the team.

“Nah, I’ve got to keep on working,” he said. “I’ve done everything I can to plead my case. Now I’ve got to just keep on working and hopefully they like me enough to keep me.”

For Josh Boyce, a rookie wide receiver out of Texas Christian University, Thursday’s game didn’t involve drama. A fourth-round pick with great promise (and speed), he has been touted since his selection as someone who can impact this team immediately.

And he showed why against the Giants.

In the second quarter, he made a move off the line that froze veteran Terrell Thomas and raced down the sideline to snag, with his finger tips, a 40-yard touchdown pass from Ryan Mallett.

“Ryan threw a great ball, I just tried to make a play,” he said. “He threw it pretty deep so I just tried to go get it.”

Earlier, he took a hand-off around left end for an 18-yard gain. On each play, he displayed the speed and ability that everyone has raved about.

Boyce is one of a trio of rookie wide receivers — including the undrafted Thompkins and Aaron Dobson, a second-round pick out of Marshall — who will be Brady’s new targets. They have all had their moments in camp.

Asked if there’s some competition among them, Boyce laughed.

“It’s a friendly competition and we always try to push each other,” he said. “Three rookies, all with the same goals, so we’re always pushing and being hard on each other.”

They’ll be on the team next week, the Patriots’ future squarely in their hands.

Others? We’ll soon find out.