Chris Egan of King-5 TV in Seattle has confirmed Broncos receiver Brandon Marshall's arrival by seaplane at Seahawks headquarters, and he thankfully did it without reference to the team making a splash in free agency.
Marshall is a restricted free agent tendered to a first-round draft pick, meaning the Seahawks would have to risk the sixth overall choice -- not the 14th, acquired from Denver via trade -- if they signed the receiver to an offer sheet. I would be shocked if Seattle took that route, particularly absent a market for Marshall. Working out a trade with Denver would make much more sense.
The Seahawks will spend the afternoon getting to know Marshall and renewing acquaintances (their offensive coordinator, Jeremy Bates, coached Marshall in Denver). Seattle might be wise to let the market for Marshall become more clearly defined. I haven't seen reports suggesting additional teams have serious interest. The Ravens acquired Anquan Boldin, diminishing any interest they might have had for a receiver with Marshall's credentials.
The Seahawks know Denver wants to trade Marshall. They know Marshall wants out of Denver badly.
Those circumstances could make it plausible for the Seahawks to negotiate a lower price for Marshall. The Antonio Cromartie situation in San Diego could be instructive here. The Chargers wanted to trade him. Cromartie, like Marshall, carried baggage. The Chargers wound up settling for a 2011 conditional draft choice.
Marshall should have more value than Cromartie, but how much more? It's an upset if Seattle parts with a 2010 first-round choice under the circumstances.