FOXBOROUGH, Mass. — Opening day in Miami saw the New England Patriots get upset by the upstart Dolphins. New England led 20-10 at halftime but was shut out in the second half and lost 33-20.

A little more than three months later, New England is at 10-3, where it generally is this time of year, and the Dolphins are 7-6. The Patriots can clinch the AFC title with a win over the Dolphins on Sunday in Foxborough and maintain the inside track to the No. 1 seed in the conference.

But a problem that was a major factor in that opening day loss — pass protection — has become a growing issue again over the last few weeks.

Much of the Patriots’ early-season struggles, including the 2-2 start after a blowout Monday night loss in Kansas City, could be traced back to the offense line. The unit had new bodies and a new coach. The results were not good.

But the group pulled itself together in the Patriots’ seven-game winning streak in the middle of the season. Fourth-round rookie Bryan Stork took over the starting job at center. Veteran and team captain xxxxxxx slid into Logan Mankins’ former spot at left guard. And Ryan Wendell, a starter at center the last two seasons, bumped out to the right guard spot.

After being sacked four times on opening day and 10 times in the first four weeks, quarterback Tom Brady sacked just six times in New England’s seven-game winning streak.

And while he technically was sacked just twice in the last two weeks — a 26-21 loss in Green Bay and a 23-14 win in San Diego on Sunday night — Brady was under far more pressure than the sack numbers would indicate. He was hit six times in Green Bay and another five times in San Diego. He was hurried endless other times.

Brady felt the pressure and his play — and that of the entire offense — declined. An attack that had scored 34 or more points in four straight games and six of its previous seven contests was suddenly held in the low 20s. The unit had four straight three-and-outs in the third quarter against the Chargers and has had 12 drives with one first down or less in the last two weeks.

Left tackle Nate Solder gave up the edge consistently in Green Bay and then again Sunday in San Diego, regularly losing one-on-one battles with Chargers ends Melvin Ingram and Dwight Freeney.

It’s a growing concern for outside observers, especially fans who have seen Brady’s play decline in big games over the years against teams that can put pressure on No. 12.

But according to Patriots offensive coordinator Josh McDaniels, Solder and right tackle Sebastian Vollmer have been showing consistent improvement.

“I think both of our tackles have been playing increasingly better as the year has gone on and I’m really happy with what they’ve been able to do,” McDaniels said. “Certainly, they have to block a lot of marquee players on the edge. … Our tackles have to do a great job of protecting the spot for Tom to be able to step up and throw. It’s a great challenge every week. San Diego was no different. Ingram and Freeney and Jarret Johnson and the guys that they were dealing with there have great motors, different styles of rushers.

“Again, there are going to be some good players on the other side of the ball that every once in a while they’re going to get you. That’s why it’s a team game. And the quarterback knows that those guys are going to make some good plays as well and usually does a good job of getting the ball out of there and helping those tackles out once in a while when they need it. I’m very pleased with the way those guys are playing. I think they’re doing a nice job on some really good players, and they’re going to have an incredible challenge on their hands this week with the guys we’re going to see on the edge from Miami.”

Miami ranks 11th in the NFL in sacks per pass play. The front is led by Cameron Wake’s team-best 9.5 sacks, while Olivier Vernon has 6.5 on the other end.

The Patriots’ offensive line, whether it’s struggling as some think or improving the way that McDaniels described, certainly has something to prove to avoid New England being swept by a division opponent in a season for the first time since 2000.

“They’re a team that they don’t have to blitz to get pressure on you, which I would say is a great luxury,” McDaniels said. “There are teams in the league that need to pressure more to create issues for the quarterback in the pocket. This team doesn’t have to do that. They have really good edge rushers; they have good interior rushers. Their whole group has been productive up front. This is as good a group as we’re going to play in terms of the depth of it and their effectiveness in terms of getting to the passer.”

“We’re going to have an issue. We’ve got to handle them up front, block them, allow the quarterback time to throw when they don’t pressure. There are a lot of issues they give you in the passing game as you’re preparing for them. We’re going to have to have a great week of preparation. We’re going to have to play a lot better than we did in the first contest.”

And turn around a trend on offense that has seen Brady under more pressure in recent weeks, leading to a dip in scoring for a team that had been putting up points as fast as in the game just a few weeks earlier.

NOTE: Among those who did not practice Wednesday was RB LeGarrette Blount, who was tending to legal charges related to his marijuana case in Pittsburgh.