What looked like the start of something special just over a month ago has instead turned into a complete disaster for the Chicago Bears.

While it's safe to say injuries have derailed Chicago's season, the Minnesota Vikings can only hope a serious knee injury suffered by Adrian Peterson doesn't hinder them in 2012.

Already eliminated from playoff contention, the visiting Bears try to snap their longest losing streak in nine seasons Sunday against a Vikings team looking to overcome Peterson's absence.

Chicago (7-8) appeared headed for the postseason after improving to 7-3 with a 31-20 win over San Diego on Nov. 20, but rather saw its season start to spiral downward that weekend. Jay Cutler suffered what proved to be a season-ending broken right thumb, and the Bears have since dropped five straight to drop out of the playoff race.

Matt Forte's sprained right MCL in Week 13 certainly didn't make things any easier on Chicago, which finds itself in the midst of its worst single-season skid since dropping eight straight Sept. 22-Nov. 18, 2002. Both Cutler and Forte were placed on injured reserve Tuesday.

"It's tough," offensive lineman Roberto Garza said. "We had a lot of big goals for the season. We had a lot of injuries, but that doesn't matter. We have to step in, guys have to step up and make plays. We haven't done that. We haven't been able to score enough points. We haven't been able to finish plays. Obviously, it falls squarely on us."

The Vikings (3-12) were dealt a huge blow of their own when Peterson tore the ACL and MCL in his left knee during last Saturday's 33-26 win at Washington. With its playoff chances long gone, Minnesota can only hope to have its most dangerous offensive threat back by the start of next season.

"He sets his goals extremely high and he's one of those guys who, when he puts his mind to it, there's no reason to ever doubt that he can achieve what he sets his mind to," said coach Leslie Frazier, whose team snapped a six-game losing streak by defeating the Redskins.

"We're looking forward to his attacking this rehab like he's attacked every offseason, to come back and play and be even better than he was before. I know with (head trainer Eric Sugarman) and our medical staff, they're going to do everything they can to get him back on the field and ready to go when we line up in that first football game next season."

Toby Gerhart posted a career-best 109 rushing yards on 11 carries after replacing Peterson last weekend and is expected to see the majority of the workload Sunday.

Rookie quarterback Christian Ponder (concussion-like symptoms) was also forced from the victory, opening the door for the versatile Joe Webb. Webb completed 4 of 5 passes for 84 yards and two touchdowns to go along with 34 rushing yards and another score.

Ponder passed concussion tests this week and Frazier said he remains the team's No. 1 QB, but the coach certainly seemed intrigued by Webb's play Sunday.

"Some of the things he does, and what it does to the rest of our team, you can't ignore," Frazier said after the game. "So it's something we're going to have a real hard look at as we go forward. He definitely lifts our team."

Chicago, in contrast, hasn't received much of anything from its backup quarterbacks.

After watching Caleb Hanie compile a dreadful 41.8 quarterback rating over the previous four weeks, the Bears went with veteran Josh McCown during last Sunday's 35-21 loss at Green Bay.

McCown threw for 242 yards with a touchdown and two interceptions. While some Bears fans are eager to see what fifth-round pick Nathan Enderle has to offer, McCown is all but certain to start again Sunday.

McCown, who was coaching football at a North Carolina high school before signing with the team in November, could be auditioning for the second-string job next season.

"We've got one more game, and I'm interested to see how he performs," general manager Jerry Angelo told the team's official website.

"We'll have time to make that decision, and hopefully we're going to see another good performance Sunday."

Chicago would also love to see Kahlil Bell, who started in place of the injured Marion Barber (calf), build on last week's display. Bell rushed for a career-high 121 yards on 23 carries and could be in for another big day against a Vikings defense that has surrendered an average of 146.8 rushing yards over its last four home games.

Minnesota, which is 1-6 at home, hasn't concluded its home schedule with fewer than two victories since going 1-4-2 in 1967.

Vikings defensive end Jared Allen will be the team's lone representative at the Pro Bowl. He leads the league with 18 1/2 sacks.

Chicago, meanwhile, had five selections in cornerback Charles Tillman, linebackers Brian Urlacher and Lance Briggs, special teams stud Corey Graham and Forte.

Forte, who recorded 1,487 yards from scrimmage and a team-best 52 receptions before going down, is the first Bears Pro Bowl running back since Neal Anderson following the 1991 season.

Chicago has outscored Minnesota 142-67 in taking four straight in this series -- including a 39-10 win Oct. 16.