FOXBOROUGH, Mass. (AP) - A New England Patriots defense that gave up so many big plays is finally making them. Just in time.

The Patriots began the regular season with an influx of rookies they hoped could improve one of the worst teams at allowing yards last season. They ended it with their first shutout in three years and a boost of confidence heading into the playoffs.

"We've improved each week," defensive back Devin McCourty said, "but I think the most important thing is this time right now, how much better can we get going into these last games.

"We can't afford to come out and have one bad game."

New England's defense had one of its best games in Sunday's 28-0 win over the Miami Dolphins that brought an opening-round bye. The Patriots (12-4) had a season-high seven sacks, gave up just 106 yards in the first half while going out to a 21-0 lead and let the Dolphins cross midfield on just two of their 11 possessions.

Pretty good for a team that gave up 38 plays of more than 20 yards in the first half of the season. That number dropped to 28 in the second half.

The improvement on third downs also has been impressive. Opponents converted at a rate of 50 percent or higher in six of the first 10 games. But no team was better than 38 percent in the last six.

Credit that to youngsters gaining experience, veterans settling into roles and communication and cooperation growing.

First-round picks Chandler Jones at defensive end and Dont'a Hightower at linebacker started 13 games. On Sunday, Hightower recovered a fumble at the Patriots' 1-yard line, preserving the shutout.

Second-rounder Tavon Wilson at safety and seventh-rounder Alfonzo Dennard have become productive players. Even Justin Francis, a rookie free agent, made an impact at defensive end with the first three sacks of his career on Sunday.

He had plenty of help.

"You can single out anybody with stat numbers," defensive coordinator Matt Patricia said Monday, "but if you take a look at the group effort, it was really what we were looking for.

"You can certainly see situations where the guys in coverage in those situations did a really excellent job to allow the pass rush time to get to the quarterback and then you can see situations where the pass rush was able to get to the quarterback, which allowed the cover guys to not have to cover as long. So, I really think it was a good, collaborative effort."

Last season, only one team, the Green Bay Packers, allowed more yards than the Patriots. The fact that 17 teams gave up more points didn't mask the weaknesses.

So coach Bill Belichick took defensive players with the first six of his seven draft picks.

He also added veterans before the season - safety Steve Gregory and defensive end Trevor Scott - and traded for cornerback Aqib Talib after the ninth game, a move that allowed McCourty to move to safety where he solidified the secondary.

It also made a defense with solid backups even better.

Scott stepped in when Jones was sidelined for two games and Jermaine Cunningham was suspended for four after violating the NFL policy on performance-enhancing substances.

"We have a lot of depth here on defense," Scott said. "If someone goes down we have the next guy that's going to step in and fill his role. So it's definitely huge to have the depth that we have. No matter what happens we just need to keep moving forward."

They may have to do that without defensive end Rob Ninkovich. The team leader with eight sacks left Sunday's game with a hip injury and didn't return. There was no update Monday on his condition.

At least he has extra time to recover after the Patriots earned their sixth bye in Belichick's 13 seasons as coach.

"It'll be a good time to get everybody back into shape," Scott said. "We're not taking the week off, that's for sure. We're still going to be back in here working hard and getting ready for whoever we face next."

The players return from a New Year's Day break for two days before taking three days off. By the time they come back on Monday, they'll know the identity of their opponent at home on Jan. 13. They'll play Houston if the Texans beat the Bengals on Saturday. Otherwise, the opponent will be the winner of the wild-card game between the Baltimore Ravens and Indianapolis Colts on Sunday.

The Patriots already have played all three potential opponents.

"I never really kind of rely on that," left tackle Nate Solder said. "I always go back and I study the same film and prepare as if I hadn't played them."

Derrick Martin only played against one of them. The Patriots signed the veteran safety after the eighth game and he has played in just five games since then. But he had a sack on Sunday, one of six by substitutes.

"It's good to have those guys on your team that maybe necessarily don't get all the reps but that can step in and just be able to function at a high level," Patricia said.

And help turn a once shaky defense into a stingy one.