NFL Free Agency: Oakland Raiders' Stephon Heyer and the Top 5 Linemen QBs Hate

Jason Campbell put 3,000 miles of space between himself and the Washington Redskins when he was traded to the Oakland Raiders in 2010.

Turns out it still wasn't enough to escape Stephon Heyer, a 6'6", 320-pound turnstile at right tackle who followed in Campbell's footsteps this offseason by signing with Oakland as a free agent.

On most plays, calculating sacks allowed is a subjective game of finger-pointing. Quarterbacks shake the dirt off and scowl in whichever direction the hit came from; linemen claw and scratch to hold off pass rushers and wonder why the ball hasn't been thrown yet.

But in a few special cases, like Heyer and Campbell's seasons together in Washington, the quarterback already knows the hit's coming—and the commentators, the opposing defensive coordinator and the fans in attendance already know whose fault it is.

Some guys just aren't cut out to set the edge.

Fortunately for Campbell, Heyer projects as a backup behind the Raiders' twin 6'9" towers Jared Gaither and Jared Veldeheer. But here are the top five potential starters who'll have their quarterbacks wanting to scurry 3,000 miles away to safety in 2011.

5. Michael Oher: Ravens' Joe Flacco Feels Promising Tackle's Growing Pains

Let's be clear: Michael Oher isn't on this list to say he doesn't have the makings of a great lineman.

He absolutely does.

It's just that the seven sacks he allowed on Joe Flacco's blind side (pun incidental) in 2010 paced an offensive line that let opposing pass rushers through for a whopping 121 quarterback hits or sacks, one of the worst totals in the NFL.

Watching Oher, he flashes the length, strength and technique to manhandle All-Pro defenders like Pittsburgh's James Harrison. In fact, Oher shut Harrison down in their two regular season clashes last year—but the Steelers' linebacker got his revenge, notching three sacks when they met in the playoffs.

Flacco's tendency to hang onto the ball a bit too long in the pocket hasn't done his linemen any favors. But once Oher consistently plays up to his All-Pro potential, Baltimore's quarterback will breathe a little easier back there against any opponent.

4. Winston Justice: Eagles' Awkward Second-Rounder Sends Michael Vick Scrambling

When Winston Justice's name comes up, it's most often associated with New York Giants defensive end Osi Umenyiora.

As in the four sacks and constant quarterback pressure Justice surrendered to Umenyiora back in 2007, a scarring and utterly underwhelming performance in his first NFL start.

At the time, former All-Pro Philadelphia defensive end Hugh Douglas quipped, "If they don't bite when they're a puppy, they won't bite when they're a grown dog. To me, [Justice] is not even a football player."

Since then, Justice has started 14 more games and improved enough that the Eagles signed him to a four-year, $18 million contract extension in 2009. Switching to right tackle took the "blind side" pressure off the much-maligned lineman—until left-handed Michael Vick became Philadelphia's starter last year.

It's a bit of a chicken-or-the-egg argument as to whether a hot-footed running quarterback like Vick brings sacks on himself or if it's his line that's to blame. But the Eagles' 49 sacks and 101 hits allowed suggest having Justice behind him didn't exactly put Vick at ease in the pocket.

If athletic free-agent signing Ryan Harris can't stay healthy—and he hasn't in either of the past two seasons—Vick will be in for more of the same.

3. Jeff Backus: Lions' Twice-Stung Matthew Stafford Hopes Third Time's the Charm

Over the past three offseasons, the Detroit Lions have been giving Jeff Backus votes of confidence.

They've passed on first-round linemen such as William Beatty of the New York Giants in 2009, Seattle's Russell Okung in 2010 and New England's Nate Solder this past April.

According to head coach Jim Schwartz, Backus has turned in at least one Pro Bowl year over that span as the Lions' sacks allowed totals have steadily declined. Last season, Detroit's offensive line was one of the NFL's stingiest units against pass rushers, giving up only 27 sacks.

But you'll forgive 2009 first overall pick Matthew Stafford if he hasn't learned to trust his oft-maligned left tackle yet.

The whispered worry about Stafford is that he's "injury-prone," having ended each of his first two NFL seasons on the Lions' injured reserve list. It's a bit unfortunate, then, that the lineman who allowed both of the hits that sidelined Stafford will be suiting up to block for him again in year three.

By all accounts, Backus has been better. But would you trust him if you were in Stafford's shoes?

2. Levi Brown: Cardinals' Kevin Kolb Won't Be Blind to Bad Bookend

Unlike the first three names on this list, there's little upside to discuss about Arizona's Levi Brown.

Brown, drafted just two slots behind the Cleveland Browns' franchise left tackle Joe Thomas in 2007, was a punishing 6'6", 324-pound run-blocking specialist as a rookie.

The Cardinals stuck him at right tackle in front of right-handed quarterback Kurt Warner and made a Super Bowl run the next year.

Four years later, Brown's still a run-blocking specialist stuck at right tackle. Arizona's attempt to transition from Warner to left-handed former first-rounder Matt Leinart went awry for a number of reasons, but Brown's swing-and-miss tendencies on Leinart's blind side didn't help.

Having signed former Philadelphia Eagles backup Kevin Kolb to a six-year, $65 million contract ($21.5 million guaranteed), the Cardinals will breathe a little easier knowing their chosen righty won't be turning his back on Brown in the pocket.

1. Charlie Johnson: Vikings' Trust in Former Peyton Manning Protector Misplaced

When Bryant McKinnie reported to the Minnesota Vikings' training camp in terrible shape after this summer's lockout, he put the team in a bad spot.

Behind McKinnie, Minnesota's only alternative at left tackle seems to be Charlie Johnson, a free-agent acquisition who started 54 games in five seasons with the Indianapolis Colts.

According to the most basic statistics kept for offensive linemen, it seems like a bit of an upgrade on paper. The Vikings (particularly McKinnie) didn't do a great job of protecting their quarterbacks in 2010, while Johnson's Colts allowed the NFL's fewest sacks.

Seems like Donovan McNabb, whose Washington Redskins' 46 sacks allowed put them among the league's worst last season, would appreciate a bit of Peyton Manning's pass protection.

Among the many ways McNabb isn't Manning, one of the foremost is his internal clock. Where Manning consistently gets the ball out of his hand around two seconds after the snap, McNabb has been known to take his time.

Plop a stocky, guard-sized lineman on the side of the line that McNabb can't see, as the Vikings seem set to do, and watch that stingy sacks allowed number from Indianapolis regress to the mean. Hard.

But as always, whether it's Johnson's chicken or McNabb's egg that's really to blame is hard to say.