People will ask, "So what do you look for when you're standing there baking in the sun on the sidelines at training camp?"

Good question. And it's gotten better as the NFL has dialed down the number of practices, the amount of contact — Adrian Peterson will barely be grazed by an extended fingernail until opening day — and all other forms of practicing that closely resembles live NFL action

Practice is about getting all the minds to the point where all the bodies will react instinctively and cohesively once the reins are dropped. But the line of scrimmage is still a place where one can watch battles and be guaranteed of gleaning some worthwhile information from training camp. Granted, it would be noteworthy if the quarterback went 0-for-20 on the day, but, generally, it's tough for me to get a whole lot out of watching a quarterback when he's wearing a red don't-touch-me-or-you're-in-big-trouble jersey.

Years ago, Mike Tice came over to a few reporters and told us to stand exactly even with the line of scrimmage and note the general direction it moved once the big fellas starting pushing and shoving. That advice seems particularly relevant and useful for this year's Vikings training camp.

Two years ago, coach Mike Zimmer's No. 1 priority was the defensive line. A lot of work from the coaches, scouts and General Manager Rick Spielman turned that unit into the deepest and best overall unit on the team, I think. That's why I wrote today about the defensive line and why I think the key to the team's first Super Bowl appearance in 40 years rests on the same unit that was the guiding heartbeat of the Vikings' four Super Bowls.

I'll look at Bridgewater's right arm. But when the pads go on in a couple days, I'll be looking at Linval Joseph's big right toe.

As linebacker Anthony Barr told me yesterday, "Linval makes All-Pro if he doesn't hurt that big toe last year." He's right. But Joseph did suffer the turf toe injury and miss four of the last five games while the run defense finished 17th.

For this team to take the next step, the run defense has to improve. Defensive line coach Andre Patterson said it needs to be top 10. For that to happen, Joseph needs to return to form. That's what I'll be looking for. He sets the defense. If the run defense improves, there are more third-and-longs, more three-and-outs and more possession time for the offense. If the run defense fails, the Vikings fall behind, get out of whack and put too much pressure on the offense.

I also will be watching the line of scrimmage to see how the offensive line — this year's No. 1 rebuilding priority — performs against one of the top defensive lines in the league. Don't underestimate how much this can help the revamped offensive line improve.

"Coach Zimmer sets up practice so it's very competitive," offensive coordinator Norv Turner said Thursday. "That's when you're at your best, when you have great competition. You're working your butt off to keep from getting embarrassed."

That's where my eyes will be focused a lot in the next week or so.