Brad Childress said he's not losing any sleep over Brett Favre's health.

Don't believe him.

Sometime before 3 p.m. on Sunday, Childress will make the biggest decision of his career, one that will affect NFL history and perhaps how Childress is viewed in his locker room and in the Vikings organization.

As he nears the midpoint in what has been the Vikings' most disappointing season since 2001, the year Denny Green was fired, Childress may even be facing a decision that affects his job status.

At least in public, Childress has couched the decision purely in football terms. He will assess Favre's health and readiness and choose between Favre and backup quarterback Tarvaris Jackson.

That is the way a fantasy football owner would make the decision. The reality Childress faces is far more complex.

Although he has downplayed it, Childress will have to consider history: Favre's record streak of 291 games started, and Favre's past ability to play well despite injuries.

Childress seems more interested in judging Favre by recent history. Favre reported late to camp, committed 14 turnovers in six games, and ranks 30th in the NFL in passer rating. Only a quarterback of Favre's fame and charm could become a sympathetic figure while performing so poorly.

Friday, Favre was able to throw passes during the early part of practice -- the part open to reporters. He limped through the locker room later, but with Favre, we don't know whether he's in need of a leg transplant or just playing Keyser Söze.

Childress did not offer many details about Favre's performance in practice, or which way he is leaning. The Star Tribune reported in Friday's editions that Childress is leaning toward starting Jackson, which is highly logical.

Neither the current version of Favre nor Jackson figure to beat the Patriots on Sunday in Foxborough, where quarterback Tom Brady has won 23 consecutive regular-season starts.

If Jackson plays and loses, he will have gained experience and allowed Favre a two-week period in which to heal. That would give the Vikings offense a chance to excel during the last nine games of the season, when the schedule becomes easier, Sidney Rice could return and the mediocrity of the NFC and the North division should allow the Vikings to contend.

If Jackson somehow beats the Patriots, the Vikings will have achieved the proverbial "win-win," gaining an important victory while resting Favre.

If Favre starts, the Vikings' season -- their "all-in" season -- is in jeopardy.

The Vikings have struggled to protect Favre this year. Putting an immobile 41-year-old quarterback just out of a walking boot in front of the Patriots' varied blitzes, on the road, could lead to more serious injury. If Favre graduates from a walking boot to a body cast, the season could be lost.

Childress' problem isn't making a wise football decision. His problems extend into the realm of perception, and into the back rooms of an organization without a clear-cut football boss.

If Favre wants to play and Childress starts Jackson, here are the potential ramifications:

Favre's disdain for Childress becomes even more obvious.

Ten months after Childress came within one play of coaching in the Super Bowl, Favre has already persuaded many in the national media that Childress is a weak and officious leader.

What if Favre decides to (further?) discredit Childress in the locker room, either subtly or overtly?

The Wilfs disagree with Childress' decision.

Zygi Wilf agreed to give Favre a raise to at least $1 million per game for the 2010 season. Wilf is at heart a fan, and is thrilled to have Favre on his team.

Will he be thrilled to pay Favre $1 million to stand on the sideline when the quarterback insists he can play?

Can Childress afford, as a head coach, to cede such decisions to his owner? Can he, as an employee in a high-turnover business, afford not to?

A front office that will never forget the 12-men-on-the-field penalty that led to the game-losing interception in the NFC Championship Game could sense a chance to remove Childress and replace him with either a more proven or pliable coach.

This has been a rough year for Childress. He has taken the Vikings from six to eight to 10 to 12 victories and yet he's known mostly for angering Favre, and for making poor sideline decisions.

Now Favre, who so recently seemed like Childress' savior, is ruining a potential championship season and Childress' national reputation along with it.

Favre has beautifully positioned himself. If he plays, he's our valiant football warrior. If he doesn't play, he can blame Childress for being a control freak with no appreciation for history.

Childress can't win, not while coaching Favre, and both Favre and Childress know it.

Jim Souhan can be heard Sundays from 10 a.m. to noon and weekdays at 2:40 p.m. on 1500ESPN. His Twitter name is Souhanstrib. •