Vikings coach Leslie Frazier won't demand perfection. But he is hoping his team can play "a clean football game" Sunday when it heads to St. Louis. And by clean, Frazier means he wants to see the elimination of costly turnovers.

In five road losses this season, the Vikings turned the ball over 10 times and are minus-6 in turnover differential.

In their six home victories? The Vikings have 12 takeaways and eight turnovers.

Said Frazier: "Finding a way to be plus in the turnover ratio would be a big deal to us, if we can execute the way we have. Even in some of our games on the road, we've executed well at times. But we haven't done a good job when it comes to winning that turnover battle. And it's cost us."

Most notably, two weeks ago in Green Bay, the Vikings let a key division game slip away because of two costly Christian Ponder interceptions -- one in the end zone and the other at the Packers' 14.

"Our margin for error is not very big," Frazier said. "So when that happens, it becomes problematic for our football team."

Twice this year, the Vikings have gone without a turnover. Both times, they never trailed and scored convincing victories over Detroit.

Said receiver Michael Jenkins: "We've got to find a way to play better on the road. I don't know, [maybe] we could take the Metrodome name wherever we go and put it on other peoples' stadiums."

Ponder evaluation Frazier again emphasized the positive with Ponder, pointing to what he called a key drive that began late in the third quarter of the Vikings' 21-14 victory over Chicago on Sunday.

The Vikings, leading by 14 points, got the ball at their 1-yard line with 48 seconds left in the third quarter. On the drive Ponder had two throws to Jenkins on third downs, both of which resulted in first downs. The first was an 8-yard completion on third-and-7 from the 4-yard line. Six plays later Ponder hit Jenkins for 10 yards on third-and-6.

The Vikings drive ended on the Chicago 41, resulting in no points. But it did have a big impact on field position. Chris Kluwe's ensuing punt was downed at the Chicago 5.

"What he did in that fourth quarter, when we had those third-down conversions, that was big for our football team," Frazier said. "It allowed us to possess the football. We were in a backed-up situation. ... It was a major part of our being able to win that game."

Cornerback issue The concussion sustained by A.J. Jefferson against the Bears could test the team's depth at cornerback.

Chris Cook is not going to be available to come back from his broken arm until the Dec. 23 game at Houston.

Frazier said he's hopeful Jefferson will pass the concussion protocol this week, but that kick returner Marcus Sherels would be a likely replacement. Brandon Burton will also get repetitions in practice this week.

Sherels has started three games in his career, all of them last season. Burton has appeared in 14 games the past two seasons, starting one.

Milestone watch With three games left, here are the milestones Adrian Peterson is chasing. He's at 1,600 rushing yards for the season needing 161 (an average of 53 per game) to set his own single-season record.

Peterson needs an average of 133 yards per contest to reach 2,000. And he'd need 506 yards (an average of 169) to break Eric Dickerson's single-season rushing record.

Vikings add Maverick The Vikings added tight end LaMark Brown to their practice squad. Brown played three years at Kansas State before finishing his college career last year at Minnesota State Mankato as a wide receiver.