The past couple seasons, the Raiders have not been able to get consistent play from the tackle spots. Donald Penn had a great season at left tackle in 2014, but the right tackle spot was a revolving door. Last season the Raiders had two decent options at right tackle before losing Menelik Watson to injury and having Austin Howard take over and start most of the season.

At midseason, the Raiders offensive line was performing considerably well across the board. But over the latter half of the season, it faltered. Penn appeared to be wearing down first, then Austin Howard was injured and the right side went as well.

What the Raiders are left with is again hoping former second round pick Menelik Watson can finally get healthy, and if not, Austin Howard can once again step up and start at right tackle. Having those two options actually makes the right tackle spot somewhat secure for the time being. But Penn has completed his 2-year deal and the team must consider locking up a left tackle long term.

There is no doubt Cordy Glenn is the top left tackle who is set to hit free agency. But, there is no way the Bills let him out of their sight. He will either be slapped with the Franchise Tag or be stay in Buffalo long term. So, probably best to put him out of your mind.

Here are the top tackle targets for the Raiders this free agency period.

Not once during his six seasons has anyone questioned his ability to stay at left tackle, though to be fair, the Seahawks have not had another notable tackle or guard during the last six seasons; the ones that they did have -- James Carpenter, Justin Britt, Breno Giacomini -- all underwhelmed. If any of them dominated, it would be interesting to see if they would have done something with Okung earlier because while he's been pretty good, he still leaves something to be desired. He's been one of the highest paid players on the team from day one and missed 24 regular season games due to injury. He's also had a problem with dumb penalties like false starts. And the truth is that while Okung is far from perfect, he's still probably one of the top 12 left tackles in the NFL, which is very valuable these days. Okung is going to be 29, but he should have 3-4 more viable years left, meaning he will want to get more money upfront. However, there could be an issue with savvy negotiations from his camp: He is his own camp. Okung is representing himself and he's already made one mistake by mass e-mailing all 31 other teams before free agency. - Kenneth Arthur, Field Gulls

There is a more positive way of looking at Okung's injury history. Only once in the past five seasons has he missed more than three games in a season. In 2012, when he played 15 games, he was a Pro Bowler. The one season among them in which he missed 8 games was in 2013 when he returned by midseason and was the starting left tackle on their Super Bowl run. He was again their starting left tackle the following season when they returned to the Super Bowl. He has started every Seahawks playoff game in his career - a total of 12, with an 8-4 mark and a Super Bowl ring to show for it.

Last season, Kelechi started the season slow while playing through a knee injury. In Week 14, with LT Eugene Monroe proving injury prone and unreliable, the Ravens kicked Osemele out to left tackle, the position he played at Iowa State. He fared reasonably well over the final 4 games at the toughest position on the line, helping to give the Ravens backup QBs time in the pocket and establish a better run game with mauling guards Ryan Jensen and Marshall Yanda. Pro Football Focus rated Osemele with a 93.0 grade in 2015 and rank him as the 3rd best offensive unrestricted free agent behind only WR Alshon Jeffery and LT Cordy Glenn. The Ravens front office did begin contract discussions with Osemele before the late season shift to Left Tackle, but GM Ozzie Newsome admitted at the State of the Ravens Press Conference that they had the same discussions with WR Torrey Smith and OLB/DE Pernell McPhee last year before they signed with other teams. The Ravens live by the "Right Player, Right Price" strategy. - Vasilis Lericos, Baltimore Beatdown

Just 26 years of age and has the versatility the Raiders covet. They could sign him as a left tackle with the flexibility to move him to right tackle - where he played his rookie season - or either guard position. Right now, he is coming off playing some pretty good left tackle so the Raiders should be among those teams giving him a long hard look for that spot. He has a couple NFL contracts left in him and is just entering his prime.

Donald Penn, Raiders

The primary concern about Penn is if his struggles late last season was a sign of his decline. He will be 33 years old and the Raiders must begin planning for the future at the position. Should neither of the above players become an option, re-signing Penn could be a smart move, providing the team has the flexibility to move on from him at any time without too much dead money left behind. Then they could see if a good tackle is on the board when they select in the draft - whether at 14 overall or later - and see how the competition plays out.

Technically putting Long on the "Wish list" is not entirely accurate. He'd be more of a contingency plan. This former All Pro and 4-time Pro Bowler has started just 7 games over the past couple seasons. In 2014, it was injury that had him out and the Rams moved on from him. Last season with the Falcons, he simply couldn't break the starting lineup, appearing in just 4 games with no starts as a swing tackle. At 30 years of age, and with his former elite status, some team is going to give him a shot. Unless a team is truly desperate, they won't be looking to him as their only option. He is at very least a backup swing tackle, but should it work out and he can stay healthy, he could be a valuable addition. It would be akin to when the Raiders added J'Marcus Webb late in free agency last season on a cheap one-year deal.

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