A sign that points toward Matt Kalil wearing purple?

Seven offensive tackles were voted into the Pro Bowl or played as an alternate this year. Each plays left tackle on his respective team. Five were first-round draft picks. Four were taken in the top 12. Three were among the top four players taken. And one was drafted No. 1 overall.

Miami's Jake Long was a No. 1 pick. Cleveland's Joe Thomas was a No. 3. The Jets' D'Brickashaw Ferguson was a No. 4. Denver's Ryan Clady was a No. 12. San Francisco's Joe Staley, who came into the league as a right tackle, was No. 28. The Saints' Jermon Bushrod was a fourth-rounder. And Philly's Jason Peters entered the league as an undrafted tight end with the Bills.

In other words, if you need an elite NFL left tackle, the odds say you probably shouldn't let one get away when you're holding the No. 3 pick, as the Vikings are this year.

Yes, the Vikings have bigger needs, cornerback being the most obvious and receiver ranking up there as well. But those are two positions of strength in free agency and depth in the draft.

With free agency starting March 13, it's possible the Vikings will have already taken steps to address their needs at cornerback and receiver before the draft arrives in late April. As for left tackle, well, it's pretty much a lock that they'll still have that glaring need when they're on the clock with the third pick overall.

"Usually, there are no left tackles in free agency," Vikings general manager Rick Spielman said Thursday. "If they're that good, they are usually not [available] out there."

The many options for the Vikings at No. 3 could include trading down if they can find a partner or taking Oklahoma State receiver Justin Blackmon or USC left tackle Matt Kalil if they're available.

Spielman wouldn't tip his hand, but he did explain the thought process in general when it comes to deciding between a playmaker and a left tackle.

"You weigh the decisions," Spielman said. "If [the quarterback] has more playmakers around him, does that make the left tackle better because the ball is coming out quicker and he is not getting hit as much? Or do you have a chance to pick a cornerstone left tackle, which is very important because he has to block the premiere pass rushers every week. Is that better for your club? So there are some different philosophies there."

NFL Network draft analyst Mike Mayock has watched a lot of film of Kalil and has deemed him the real deal.Kalil is a wonderfully gifted left tackle," Mayock said this week. "He has great feet, long arms and really fits the bill athletically for what you're looking for in an All-Pro left tackle. He doesn't have the core strength right now that he will have in a couple of years. So he will be bull-rushed some early on. But the bottom line is he does what the NFL requires of a left tackle: He will protect the passer."