If the Seattle Seahawks are going to trade for help at offensive tackle, they’re going to find the market fairly bare. Only four potential targets appear to be out there.

It is one thing to say “The Seattle Seahawks must find a veteran offensive tackle.” It is another thing entirely find one that is available and worth the cost. “Go sign a free agent” only works if there is a free agent upgrade available.

Lets start with potential trade targets. The Seahawks badly need upgrades at offensive tackle. The problem is that good OTs are a difficult thing to find for any team and once they have one they aren’t likely to let them go.

After scouring NFL rosters, I’ve come up with 4 potential trade targets that should interest the Seahawks. All contract information below take from OverTheCap.

Joe Thomas

Age: 32

Cap number (if traded): $8.8 million

Years remaining: 2

Joe Thomas would be a major prize for any team that can pry him away from the Cleveland Browns. The Browns don’t need the cap space, but they desperately need an influx of talent all over the entire roster.

By the time the Browns are ready to be competitive again, Thomas will have aged to a point where he will no longer be a key piece of their team. Trading him now would allow them to get multiple young players, though it is unlikely that any players in return would be as good as Thomas is now.

The Seahawks will have to be wary about giving up too much to just two years of elite LT play. The Browns will rightfully want a King’s random for the best current LT in the NFL.

Branden Albert

Age: 32

Cap number (if traded): $8.875 million

Years remaining: 2

There is no doubt that Albert is a franchise left tackle. The moment the Seahawks acquire him he’d be the best offensive lineman on the roster by a wide margin.

His fit in Seattle is at least partially dictated by his availability. Miami has need of salary cap space, and trading Albert would generate $7.2 million in cap room. It helps that the Dolphins already have his replacement on the roster.

You may remember the saga of Laremy Tunsil during last year’s draft. He was thought to be the first non-QB taken, but a video posted online during the draft sent tumbling down draft boards. The Dolphins took with with the 13th pick in the draft, and then wasted his talents by playing him at LG all season.

Joe Staley

Age: 32

Cap number (if traded): $8.25 million

Years remaining: 3

The 49ers made a mistake in my opinion by not trading Staley last season. They were going nowhere, and there were multiple teams (including Seattle) that were desperate for an offensive tackle.

Now potential trade partners will be more cautious. There are free agent options (though less talented) as well as draft options (though less certain) that will makes other team leery of sending the 49ers draft picks for good-but-not-elite left tackle.

Jeremy Parnell

Age: 30

Cap number (if traded): $6.5 million

Years remaining: 3

Parnell’s franchise-friendly contract means he isn’t likely to be traded. His salary actually goes down over the next few seasons, so the Jaguars may choose not to let him go.

He also isn’t a great player by any means. For a team as bad as Jacksonville, getting a draft pick for a player such as Parnell might just be worth it. Parnell is replaceable, and the Jaguars need to continue to add to their young core.

For the Seahawks, Parnell would provide them with a veteran RT. He’d be someone who could help the youngsters on the line develop while not reading up the resources that some of the other options would require.

Parnell would be a nice upgrade at right tackle for 2017, but ultimately he’s a stop-gap. He’d provide some stability while Ifedi improves at RG, but the team would still need Odhiambo or someone else to step up and take over the RT job in the future.