The Vikings' shattered passing offense could use the return of Percy Harvin, who was leading the NFL in receptions when he badly sprained his left ankle Nov. 4 in Seattle.

But Harvin, who missed the past three games, still is questionable this week as the Vikings prepare for Sunday's game against Chicago.

"I really don't have much new news regarding Percy," Vikings coach Leslie Frazier said Monday. "He did a little bit with our trainer today; we'll learn a little bit more as the week goes on. Hopefully, we can get him back, but there's no certainty there.

"We're a better team when he's on the football field for obvious reasons -- what he gives us a kickoff returner, it's hard to replace that, and what he does for us as a slot receiver."

Frazier said the Vikings were "relatively healthy" after their 23-14 loss in Green Bay on Sunday.

Defensive end Jared Allen, who revealed Sunday that he was playing despite a torn labrum in a shoulder, had lower back spasms as well and was scheduled for an MRI. Center John Sullivan has a rib contusion. Frazier said both players should be ready for the Bears game.

Running away Adrian Peterson's 210-yard rushing day against the Packers kept him easily in the NFL rushing lead with 1,446 yards. He is 308 yards ahead of the No. 2 rusher, Marshawn Lynch of the Seahawks, with four games remaining.

"So many great things happened with Adrian and our offensive line, the way they performed," Frazier said. "Just an incredible effort by Adrian."

Peterson is averaging a career-high 6.2 yards per carry. His best rushing season was 1,760 yards in 2008.

The 200-yard game was the fourth of Peterson's career, and he holds the NFL record of 296 yards in a game, set against San Diego in 2007.

O.J. Simpson holds the record for 200-yard games (six), and Tiki Barber had five. Peterson, Jim Brown, LaDainian Tomlinson, Barry Sanders and Earl Campbell have four.

If Peterson continues his per-game average of 120.5 yards, he would finish with 1,928 yards, eighth highest in NFL history. There have been six 2,000-yard rushers, topped by Eric Dickerson's 2,105 in 1984. Simpson (2,003 in 1973) is the only player to do it in a 14-game season.

Bears banged up Chicago's overtime loss at home to Seattle on Sunday dropped the Bears to 8-4, tied with Green Bay for the NFC North lead.

The Bears have health issues this week, with standout middle linebacker Brian Urlacher (hamstring) the latest in a string of injuries.

Cornerback Tim Jennings, who leads the NFL with eight interceptions, left Sunday's game because of a shoulder injury, and receiver Earl Bennett went out because of a concussion. The Bears already were without guard Chris Spencer (knee) and kick returner Devin Hester (concussion), and starting guard Lance Louis suffered a season-ending knee injury against the Vikings on Nov. 25 after a blindside hit from Allen.