So far this month, Seattle's subtractions said more about what Pete Carroll wanted in Seattle as opposed to any additions.

That changed Wednesday afternoon with the news that the Seahawks have acquired Charlie Whitehurst from San Diego. ESPN reported the terms of the deal, and it's a whopper. Seattle will trade spots in the second round -- which costs Seattle about 20 spots in terms of draft position -- and giving up a third-round pick in 2011.

It also cost money. Big, fat sacks of it. Seattle has agreed to a two-year contract that will pay Whitehurst about $5 million annually.

• Seahawks betting big on Whitehurst
By Mike Sando, ESPN.com

The easy route here is to express incredulity. After all, Whitehurst has not attempted a pass in a regular-season game, and has been San Diego's third-string quarterback behind even Billy Volek on the depth chart. If he can't pass a backup, how's he going to pass successfully as a potential starter, which is exactly what Seattle sees him as by virtue of what the Seahawks are parting with.

Time will tell whether the sacrifice was worth it. Nine years ago, Seattle traded away a third-round pick for a quarterback who had never started a regular-season game and had attempted all of 29 passes in that time. Not only that, but Seattle gave that guy a new contract.

The deal for Matt Hasselbeck didn't turn out to be so bad in retrospect.

Will this one work out as well?

We have our first yardstick for the Carroll era.

The Seahawks believe Whitehurst can play. They're probably not alone in this respect given that Whitehurst was a third-round choice.

Seattle preferred Whitehurst to Derek Anderson, who signed a free-agent deal for less money in Arizona without the Cardinals giving up any draft picks.

The amount Seattle gave up to acquire Whitehurst, both in terms of money and draft-pick compensation, trumps what quarterbacks like Seneca Wallace, Brady Quinn and Shaun Hill -- players with starting experience -- commanded. Those guys went for late picks, the NFL equivalent of loose change.

Seattle wheeled out a lot for Whitehurst. This isn't a test run or taking a flier. This is an investment, a bigger investment than most expected and Whitehurst is clearly a player Seattle has pegged can be a successor to Matt Hasselbeck, who is 34 and entering the final year of his contract.

A quick history review: • In 2001, Seattle gave up its first-round pick (No. 10) and a third-round pick (No. 72) for Matt Hasselbeck and Green Bay's first-round pick (No. 17) overall. The trade was made in March. In August, before Hasselbeck had played a real game for Seattle, he signed a five-year contract worth as much as $24 million with a $2 million signing bonus.

• In 2010, Seattle gave up its second-round pick (No. 40 overall) and a 2011 third-round pick for San Diego's second-round pick (No. 60 overall) and quarterback Charlie Whitehurst, who according to ESPN's reports will sign a two-year deal expected to pay him an average of $5 million per season.

What does this mean for Matt Hasselbeck? Nothing right away. Hasselbeck has one year left on his contract. Trading for Whitehurst isn't like adding a quarterback with starting experience who could make Hasselbeck expendable. I still fully expect to see Hasselbeck be Seattle's starting quarterback when the season begins.

What happens after that is a question, though. If Seattle struggles as a team, there will be pressure to put Whitehurst under center and see what happens. This isn't a rookie Seattle is getting, someone who could use the equivalent of a redshirt year. Whitehurst has time in this league and there will be a desire to see what he's got.

• The second thing is how it impacts the possibility Seattle could draft a quarterback. It would be hard to see choosing a quarterback with the No. 6 pick, given the size of guaranteed money that player would command. As it stands now, Seattle is already planning to spend about $5 million on a guy who's never thrown a regular-season pass in Whitehurst. Would they add a big-budget rookie contract to that total?