How worried should Ravens be about O-line?

The Ravens' offense relies on Ray Rice, meaning the blocking in front of him is crucial to the team's success. (MCT/Landov)

You want a durable offensive lineman? Bryant McKinnie's certainly been that. Other a four-game suspension to start the 2008 season (we'll get to that in a moment), McKinnie started every game for Minnesota from 2003-2010.

Unfortunately, McKinnie's been labeled a few other things during his NFL career: lazy, a trouble-maker, overweight.

The last one was what did him in, in Minnesota -- the Vikings released McKinnie in early August after he reported to camp weighing 400 pounds (NFL.com lists him at 335, which he probably hasn't weighed in a decade). That conditioning issue was the last straw for Minnesota, which stood by McKinnie through the 2005 "Love Boat" incident and charges of aggravated battery, disorderly conduct and resisting arrest, stemming from a 2008 night-club brawl.

McKinnie also skipped Pro Bowl practices and commitments after being voted to the team in the 2009 season, and was eventually kicked off the NFC team.

So, despite his ability to stay on the field and the role he's played in Adrian Peterson's rise, McKinnie sat on the free agent market for three weeks before Baltimore came calling. But can Baltimore count on McKinnie to get in shape and slide into the starting left tackle spot?

The Ravens don't really have another option. In his two years with Baltimore, Michael Oher's been solid but not spectacular -- partially because the Ravens shifted him to right tackle his rookie season, then back to left tackle last year and probably will move him to the right again with McKinnie on board.

On the other end of the line, it had been a battle this preseason between Jah Reid, Ramon Harewood, the recently-released Oniel Cousins and others. Nothing worked. It made sense then for Baltimore to reach out and grab McKinnie to play left tackle.

The Ravens clearly had concerns about their in-house line options.

McKinnie's signing far from solves everything.

He's still trying to shed some of those extra pounds from Minnesota. Meanwhile, center Matt Birk has been slow to return from offseason knee surgery, and right guard Marshall Yanda missed extended time with a back injury. So, with just one preseason game left before the Steelers visit Baltimore for the regular season opener, the Ravens have yet to trot out their full offensive line.

They may try to do so Thursday in their preseason finale vs. Atlanta. Even that possibility is up in the air. Either way, the O-line doesn't have a lot of time to gel.

Given how much of Baltimore's offense relies on finding space for RB Ray Rice, that has to be worrisome. Even with Joe Flacco improving year after year, this is a run-first attack. The issues up front could alter that plan.

But dropping Flacco back to look for his talented receivers is a risky proposition, too, if McKinnie isn't up to snuff on the left side. Keep in mind that because of the lockout and his subsequent release in Minnesota, McKinnie's only had about a week to get himself in shape and back up to speed. That reality could cause Baltimore issues in numerous aspects of its offense.

All indications are that Baltimore is confident enough in McKinnie's current condition to slot him in at left tackle. The alternative is to keep Oher on Flacco's blindside and continue rotating the turnstile on the right -- a scenario that sparked Baltimore's interest in McKinnie in the first place.