Making history: It's been nearly 50 years since a Vikings defense led the NFL in yards and points allowed

The current Vikings defense is on the verge of an accomplishment only Bud Grant's "Purple People Eaters" have brought to Minnesota.

Ranked No. 1 on defense in both yards (280.9) and points (16.1) allowed per game heading into Sunday's regular season finale against the Bears, these Vikings would be the franchise's first to end a season atop both NFL's defensive rankings since 1970.

Nose tackle Linval Joseph, and likely most of his defensive teammates, aren't too interested in any talk short of the Vikings' first Super Bowl championship.

"Not really," Joseph said. "I'm just worried about team ball, and I think that makes everything so much better. I'm not worried about stats."

Vikings coach Mike Zimmer said the significance is in the team's play heading into the postseason, which is strong after the Vikings forced their first shutout since 1993 last weekend in Green Bay and gave up just seven points the week before against Cincinnati.

Veteran cornerback Terence Newman, who was on the Zimmer-coached Cowboys defense that ranked No. 1 in 2003, said the ranking means little on its own. Dallas lost 29-10 in Carolina during that season's opening wild-card weekend.

"Number one is cool, but if you don't win what does it matter?" Newman asked rhetorically. "You can finish with the number one defense and go home in the first round of the playoffs."

"If you do something with it," Newman said, "OK, then you've got something to talk about."

The Vikings will start a third different center Sunday against the Bears. Starter Pat Elflein will miss his second game this season because of a lingering shoulder injury.

Elflein was held out of practice all week and, if the Vikings lock up a first-round bye, could have three weeks off between games. The rookie's left shoulder injury first popped up after the Dec. 3 win in Atlanta.

Right guard Joe Berger is expected slide over to start at center, opening up the possibility of right tackle Mike Remmers shifting inside to guard and Rashod Hill starting at right tackle. Jeremiah Sirles already is replacing left guard Nick Easton, who broke his ankle in Green Bay.

"All those guys are pretty versatile," Zimmer said. "So we'll see."

A handful of Vikings have incentives on the line Sunday, led by running back Latavius Murray, who can earn a $500,000 incentive and unlock a $500,000 salary escalator for 2018 by rushing for 169 yards against the Bears to give him 900 yards on the season.

Quarterback Case Keenum will earn another $250,000 by starting Sunday, likely ensuring he'll play 85 percent or more of the Vikings snaps this season. He has played 90.4 percent of the snaps so far.

Receiver Adam Thielen can increase his 2018 salary escalator by another $250,000 with five catches to reach 90 for the season. He's already earned an additional $750,000 for next season by reaching 80 catches.

Ben Goessling