FOXBOROUGH, Mass. — The Patriots have been at their best on offense this season when they’ve established the run and avoided facing a significant number of third downs.

Achieving success in both areas could be difficult Sunday against a Minnesota Vikings team that offensive coordinator Josh McDaniels is expecting to offer “as big a challenge as we’re going to have all year.”

The Vikings are the NFL’s stingiest defense on third down, allowing opposing offenses to convert on a league-low 28 percent of their opportunities. They are also allowing only 94 rushing yards per game, which is tied for fourth-fewest in the NFL.

One of the reasons, McDaniels said, is Minnesota’s ability to mix up its personnel and coverages. That is bolstered with talented players spread throughout its defense.

“They have a great front, they have linebackers that are very athletic, the team speed in general is tremendous,” McDaniels said. “You’re not going to outrun this group.”

The Patriots are 1-3 when converting on fewer than 33 percent of their third downs. The exception was their 27-20 season-opening win over the Houston Texans. The Patriots went just 4 of 14 on third down in that game but were able to take advantage of some early Houston mistakes in jumping to a 24-6 lead.

New England can’t count on that against Minnesota.

The Vikings have been turnover-prone at times, but Minnesota enters Sunday’s matchup with a plus-2 turnover margin. The Vikings were turnover-free in last week’s win over Green Bay. It was their first game since their Week 7 road victory over the Jets in which they didn’t have a giveaway.

New England has had to adjust offensively in recent weeks as it played through the injury-related absences of its leading rusher, Sony Michel (knee), and tight end Rob Gronkowski (ankle, back), one of Brady’s favorite options on third down.

Both were effective in their return to the starting lineup against the Jets. Gronkowski caught his first touchdown pass since Week 1, and Michel rushed for a season-best 133 yards.

“They are one of the best teams at running the ball in the red zone and one of the best teams at stopping the run in the red zone,” Vikings Coach Mike Zimmer said.

“When you can run the ball in the red zone, that typically leads to touchdowns, because you don’t get in third-and-longs and things like that where you’ve got to throw in a condensed area.”

The Patriots are also hopeful that the return of Rex Burkhead from injured reserve will provide a boost, similar to those provided by Michel and Gronkowski. Burkhead was one of New England’s go-to options in short-yardage situations last season. But he played only three games this year before suffering a neck injury against the Lions on Sept. 23.

While Burkhead’s absence hasn’t affected the Patriots’ ability to score touchdowns in the red zone (24 TDs on 38 drives inside the 20), center David Andrews said they recognize room for improvement.

“(The Vikings have) got a great defensive front, I think they play really hard, big, tough guys in there,” Andrews said. “I don’t know what the game plan is going to be yet, but whatever it is, we just have to execute it, do whatever we can up front to be at our best and be the most physical team.”