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.