By John McMullen, NFL Editor

(Sports Network) - The wheels are coming off in Minnesota.

A 5-2 start for the Vikings has morphed into a 6-6 record with a must-win game on the horizon Sunday when the Chicago Bears visit Mall of America Field.

To make matters even worse for the Vikes the team pulled the plug on Percy Harvin's season Wednesday, placing the star receiver and kick returner on injured reserve.

Harvin, a fourth-year pro, has not suited up for a contest and has hardly practiced since severely spraining his ankle in a 30-20 loss to the Seattle Seahawks back in Week 9.

At the time of his injury, the versatile Harvin was atop the league in receptions (62) and kick return average (35.9).

The Bears are plenty banged-up themselves and will arrive in Minneapolis without defensive leader Brian Urlacher among others but that may not matter since Chicago has dominated the Vikings in recent years.

Urlacher could miss the rest of the regular season after suffering a "significant" hamstring strain late in overtime during the Bears' 23-17 home loss to Seattle last Sunday. The eight-time Pro Bowler is expected to miss at least three games but hopes to be ready for a possible postseason run.

If the Bears fail to make the playoffs, however, it's conceivable that Urlacher, whose contract is set to expire after the season, could have played his last game with the team that hit the jackpot when it drafted him with the No. 9 overall pick in the 2000 draft.

"I do not think that's going to happen," Urlacher told a local Chicago TV station. "But, if it does, I have had a really good and long career so I would be sad, but I would not be crushed."

Urlacher isn't the only injury concern on Chicago's opportunistic defense. His running mate at linebacker, Lance Briggs, as well as cornerback Charles Tillman are dealing with ankle injuries, although both are expected to play. Cornerback Tim Jennings, who leads the NFL with eight interceptions, could sit, however, with a shoulder problem.

Last week Sidney Rice's 13-yard touchdown catch in overtime lifted the Seahawks over the Bears.

Jay Cutler connected on 17-of-26 passes for 233 yards and two touchdowns in the setback for Chicago, which is now tied with Green Bay for first place in the NFC North but is currently the fifth seed in the NFC in lieu of its Week 2 loss to the Packers.

Matt Forte carried the ball 21 times for 66 yards and caught three passes for 30 yards and a score against Seattle, while Brandon Marshall hauled in 10 passes for 165 yards.

The Vikings, who have lost six straight to the Bears, have hit the skids thanks in large part to the poor play of quarterback Christian Ponder.

Adrian Peterson was spectacular last week in Green Bay, running for 210 yards along with a career-long 82-yard touchdown run in the second quarter but as good as A.P. was, that's how bad Ponder performed.

The second-year pro managed just 119 yards passing, most of that in garbage time late, with a touchdown, while tossing two interceptions and hitting on just 12-of-25 attempts.

"It was a very disappointing loss," said Minnesota head coach Leslie Frazier. "We definitely want to improve our passing game. We need to create balance."

Both of Ponder's picks came with the Vikings in field goal range after long runs by Peterson, with one coming in the end zone. The embattled signal caller completed only five passes on one drive in the first half until the game was decided and Green Bay let up a bit. At one point he went nearly 39 minutes of game action without completing a pass.

"Looking at that loss, we were in that game. Some of the mistakes I made were frustrating," Ponder said. "Obviously, I'm always critical of myself, but it was such an important game, and they were such costly mistakes -- that were because of me.

"It's kind of a wake-up call. Obviously, I need to be doing some stuff differently and change my game and elevate my play, especially with where we are in the season and with the goals that are in our hands. I've got to make sure I give our team a chance to be successful and achieve those goals."

After the ugly loss Frazier expressed his support for Ponder.

"Christian is our quarterback," Frazier said. "We are going to do all we can to help him have a good game against Chicago and to help our team go out and get a win."

That was tempered a bit, however, after Frazier looked at the film of Ponder's performance, which can only be described as ghastly.

Asked if continuing to support a player performing so poorly could affect his locker room, Frazier was uncommonly truthful for an NFL coach and cracked the door for a possible change.

'I've thought about that a lot because when you're struggling at a position, the guys know how we talked about everybody doing their jobs and why it's important for us to have our success," Frazier said. "You don't want to send mixed messages at any position."

The Vikings and Bears have played 103 times overall with Minnesota holding a slim 52-49-2 advantage. Chicago, however, has won six straight in the series for the first time since Frazier was a Bear (1983-86).

WHAT TO WATCH FOR

Balance probably isn't coming this week for the Vikings with Harvin gone and Ponder still in the lineup.

In this pass-happy era of the NFL, Ponder has passed for 76 fewer yards than Peterson has rushed for over the last six games but Frazier is loathe to go to his untested backup Joe Webb.

'I think there's something there where in my mind you don't want to get into a situation where you're not sure who your No. 1 is," the coach said. "We believe that Christian is our No. 1. ... That being said, if things get to a point where your No. 1 is really costing you some situations that could preclude winning, you do have to do what's best for the football team."

Minnesota's receiving corps is extremely limited without Harvin and made even worse by offensive coordinator Bill Musgrave's personnel decisions. Rookie Jarius Wright is clearly the most dangerous receiver the Vikings have in Harvin's absence but the team continues to focus on unproductive veterans, Michael Jenkins and Jerome Simpson, who has been dealing with a nerve problem in his back.

Ponder has a disastrous 63.6 passer rating over the past seven weeks, by far the worst in the NFL so expect Peterson, who leads the NFL in rushing yards (1,446) but fumbled twice against the Bears in Chicago, to carry the load.

"It seems like he's getting better and better as the year goes along," Bears coach Lovie Smith said when talking about Peterson. "It's going to still start with him."

Chicago is ranked second in the NFL in points allowed at 16.5 per game but allowed a season-high 459 yards last Sunday.

"Obviously, you want to start fast as an offense," Ponder said, "but especially the quarterback position, getting a few completions under your belt, and having a good first and second series, establishing that rhythm. I think that will be important. But you also want to get Adrian involved; he's running the heck out of the ball."

Cutler typically excels against the Vikings' undisciplined front, using quick passes along with his legs to escape trouble. The Vanderbilt product has won five straight against Minnesota as a starter and compiled a gaudy 100.9 passer rating over that span.

With receivers Devin Hester and Earl Bennett are both dealing with concussions so Cutler will lean even more on Marshall, who caught 12 passes for 92 yards against the Vikes last month.

Also Keep an eye on Minnesota defensive end Jared Allen, who is dealing with bask spasms and playing through a torn labrum in his shoulder. Allen delivered a questionable block on Bears guard Lance Louis two weeks ago which resulted in a season-ending knee injury for the starter. Allen was eventually fined $21,000 for the borderline play.

OVERALL ANALYSIS

The Vikings are 5-1 at the Metrodome while Chicago is banged-up and not playing all the well. That said, Frazier is still looking for his first coaching win against his old team (0-4) and Cutler typically owns Minnesota. Ponder, meanwhile, is playing as poorly as any quarterback in the league and no longer has Harvin to bail him out.

Sports Network Predicted Outcome: Bears 28, Vikings 17