The concussion sustained by cornerback A.J. Jefferson against the Chicago Bears could test the team's depth at the position this week.

Vikings coach Leslie Frazier said the team will have to wait and see if Jefferson is able to pass the tests necessary to play in St. Louis Sunday. Veteran Chris Cook is not going to be available to come back from his broken arm until the Dec. 23 game at Houston at the earliest. So who plays?

"It would be Marcus," Frazier said of Marcus Sherels, the backup who has been a punt- and kickoff-returner this season. "And then, of course, we have Brandon Burton as well. So between those two, they'd get the bulk of the reps. And we'd define that as the week goes on."

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

Praising the kids

One big reason for the improved Vikings record is the play of rookie cornerback Josh Robinson and rookie safety Harrison Smith. Both intercepted passes Sunday. Smith returned his for a score, his second pick six of the season. Robinson returned his pick to the Chicago 5-yard line, setting up the team's second score.

"We're making such improvement, and we're doing it with a lot of young, young guys," defensive end Brian Robison said. "Normally it takes two, three years before you start seeing results like that. Guys like Harrison and Josh Robinson, the plays they made {Sunday}? And you look at the improvement {safety} Jamarca Sanford has made this year? He looks nothing like he did last year. Guys are making improvements and it's helping out the whole team."

Road woes

With two consecutive road games coming up, and with the Vikings believing they have to win out to earn a playoff berth, the job is simple. The Vikings have to learn to win on the road.

This season Minnesota is 6-1 at home, 1-5 on the road, with the only victory coming at Detroit Sept. 30. Over the past two seasons the Vikings are a combined 3-11 on the road.

So what will it take to win on the road?

"I think if we can play a clean football game, where we are – for a change – plus when it comes to turnovers," Frazier said. "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 has cost us. Our margin for error is not very big, and when it happens it become very problematic for our team. So I'd love to go on the road, play some clean football, and see what the results would be."

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."

An important moment?

Frazier again emphasized the positive with quarterback Christian Ponder, pointing to what he called a key drive that began late in the third quarter.

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 third-down throws to Jenkins on third downs, both of which resulted in first downs. The first was an 8-down 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."

Etc.

One of Robison's most enjoyable moments Sunday came when he led Harrison Smith into the end zone after Smith's third-quarter interception. The fact that he got to engage Bears QB Jay Cutler in the process made it even better. "Any time you can throw a block you feel like an offensive player," Robison said. "A fullback-type. So I got to see what Jerome Felton feels like."