The slide of quarterback Matt Hasselbeck should have given an opportunity to Charlie Whitehurst (Drew Sellers/Sports Press Northwest)

In choosing Matt Hasselbeck to start Sunday in Tampa, coach Pete Carroll made the safe choice.

It was the wrong choice.

“Matt’s our guy and we want him to play really well,” Carroll said Wednesday, sounding as if he were trying to convince himself as well as all his listeners. “We’re going to try to build up a great plan that he can carry out and gets us a great win.

“That’s really all I’m thinking about.  I don’t have any plan other than that.”

He should have another plan in mind – the near future of the franchise.

Not since former owner Ken Behring in 1995 hauled the team equipment to Los Angeles in a futile attempt move the franchise have the Seahawks been in a weirder position.

They are a mediocre team in desperate need of talent at many spots, yet can make the playoffs in spite of themselves. They don’t necessarily have to win Sunday to stay alive, but a loss, followed by a win next Sunday, could make them the first division with a losing record (7-9) winner in NFL history, as well as a punch-line for every TV studio wiseacre straining futilely to make a better joke.

More important than that aberration, and beyond the benefit of a home playoff game, the most significant position on the roster, quarterback, is without shape or form.

Hasselbeck is 35, at the end of his contract and floundering. Many of the reasons for his downward spiral are beyond his control – third set of head coaches and offensive coordinators in three seasons, no one good to cover his blind side, receivers that can’t stay healthy, a defense that can’t get off the field, etc.

But he’s also done enough on his own to bring into serious question his fitness for another season.

Yet his nominal replacement, Charlie Whitehurst, is neither a kid (28) nor a proven veteran. But he is a player the Seahawks have invested $8 million and two years despite the fact that until this season he had never thrown a regulation NFL pass.

As much as club management owes Hasselbeck the benefit of the doubt for his meritorious service to the franchise, they owe players and fans even more to see whether Whitehurst is a significant part of the future. One more start is a small sample size, but it will provide more knowledge than they have now.

If Whitehurst were to start Sunday and be judged a success, regardless of game outcome, the Seahawks can enter the off-season less than forlorn about the QB spot. As well, if he flops, regardless of outcome, the Seahawks have more evidence to admit the mistake and can plan accordingly.

Since the game outcome probably will be irrelevant to the next week, the risk is small.

If Whitehurst flops, the chance for veteran Hasselbeck, stung by a benching, to come in and do the superhero rescue routine is greater than the situation’s opposite – Whitehurst saving the team on the road against a quality defense.

But now, starting Hasselbeck means he must have a Matt-of-old game or face a quicker hook, even though Carroll tried to deny it.

“I don’t have any thought at all about taking the quarterback out,” Carroll said. “Not at all.”

Carroll has no choice but to say that, but fortunately for the rest of us, we have a choice whether to believe it.

Carroll is in a tough spot because he has a chance to learn a lot from this game, but unlike nearly every other mediocre team in a similar position in late December, he doesn’t have the luxury of playing the backups.

Asked what choosing Hasselbeck, after all his turnover problems, says about his faith in Whitehurst, Carroll was a little testy.

“It doesn’t have anything to do with Charlie,” he said. “It has to do with (whether) we think that Matt can get the job done for us.”

Well, the choice does have a lot to do with Whitehurst, because Hasselbeck’s experience and guts would be a better fallback position in the event that Whitehurst shatters like a Christmas ornament at the end of a cat’s paw. But they can’t trust Whitehurst yet to win them a game.

Carroll, of course, was relentless in thumping the tub for the $8 million backup.

“I’m excited about Charlie’s growth,” he said. “We trust him, we believe in him . . . he’s made good progress. He’s got better, and was very comfortable in the game last week and that’s a good sign.”

But Whitehurst came in after the Atlanta Falcons were already lighting cigars and pouring brandy. In was exhibition time, and Whitehurst was back to being Mr. August.

This freakish season has afforded the Seahawks Sunday a small-risk opportunity to see if Whitehurst can be Mr. December.

Instead, unless Hasselbeck comes through in a big way, both quarterbacks and the team potentially could be losers heading into the first official must-win game of the season on Jan. 2 against St. Louis.

Unlike college ball, where mistakes can take up to five years for the NCAA to catch up, the NFL is all about instant de-gratification.