Twenty-eight NFL teams have drafted at least one offensive lineman in the first round since 2002. The Vikings aren't one of them.

In fact, in nine drafts since they picked Bryant McKinnie seventh overall, the Vikings have taken only three offensive linemen above the fifth round. All three were second-round picks. Only one -- starting right tackle Phil Loadholt -- is still with the team.

One can't argue against drafting defensive tackle Kevin Williams ninth overall in 2003, linebacker Chad Greenway 17th overall in 2006, running back Adrian Peterson seventh overall in 2007 or receiver Percy Harvin 22nd overall in 2009. Or trading the first-round pick in 2008 for defensive end Jared Allen.

But teams typically do not put their offensive lines on the first-round back burner as long as the Vikings have. In fact, only the Chargers (2001), Giants (1999) and Titans (1993 as the Houston Oilers) have gone longer without selecting an offensive lineman in the first round.

Blame for the Vikings' 0-4 start this season or the 6-14 slide since the 2009 NFC Championship Game doesn't rest entirely on the offensive line, obviously. But there's no question the line needs to play much better overall than it has the past 20 games, especially with a new run-oriented offense that's dependent on dominating the line of scrimmage.

"I don't think any of us by any stretch of the imagination thinks we have arrived," new Vikings offensive line coach Jeff Davidson said. "There are a lot of things we need to work on."

The Vikings line is considered a hard-working unit that, like a lot of groups around the NFL, has its limitations. That's not entirely unexpected since the team has chosen only seven offensive linemen in the past nine drafts, including two current rookies (tackle DeMarcus Love and center Brandon Fusco).

Left tackle Charlie Johnson, who was thrust into the starting lineup when McKinnie was released on Day 2 of training camp, struggles with speed rushers and is built more like a guard. Left guard Steve Hutchinson is a potential future Hall of Famer, but he's also 34. Center John Sullivan is undersized and has trouble with bigger nose tackles. Right guard Anthony Herrera is a career overachiever with a nasty side that goes back to 2004 when he went undrafted. And Loadholt's three-year career has been a roller coaster from game to game, quarter to quarter.

And the backups are the two rookies, a second-year player (tackle Pat Brown) and center Joe Berger, the only reserve with NFL starting experience.

Here's how Davidson breaks down each starter:

LT Charlie Johnson (6-4, 305), sixth year, signed as free agent in July, originally a sixth-round pick of the Colts in 2006: "The one thing I truly appreciate about Charlie is he competes on every play. If it matters to them and they compete, I got no complaints about those guys. I think that's where he is."

LG Steve Hutchinson (6-5, 313), 11th year, signed as a restricted free agent in 2006, originally a first-round pick of the Seahawks in 2001: "He still does very well. In our room, he is our leader. He asks the most questions of the group. Guys listen to him. If you look at them out here [on the practice field], he's the guy who takes them over there and gets the running done [after practice]. The game is still important to him."

C John Sullivan (6-4, 301), fourth year, sixth-round pick in 2008: "I think that if you allow those [big nose tackles] to get under your pads, then, yes, it becomes a problem for John. The way that I've approached it with him and the way he approaches it is, he's considerably better than he was a year ago at this point in being able to block those big nose tackles. But he'll also tell you that he's nowhere near where he needs to be."

RG Anthony Herrera (6-2, 315), eighth year, undrafted rookie in 2004: "Obviously, I like his attitude. In fact, I love his attitude. It's a demeanor that I would like our entire offensive line to play with. And I think he brings his own level of leadership within that attitude. We feed off of him the way that he is and the approach he takes."

RT Phil Loadholt (6-8, 343), third year, second-round draft pick in 2009: "What Phil would tell you is he needs to work on a level of consistency. He'll have a number of really good blocks against the same guy in the game. And then all of a sudden he'll get off balance, he'll mistime a punch and he goes downhill from there. That's something that he needs to refocus on and be able to come back on the next play and forget the last play occurred. Whether you call that raw or whatever, I haven't gotten through to him. So I need to do a better job getting through to him."