RENTON, Wash. - Pete Carroll's already in playoff mode, even if his Seattle Seahawks probably don't deserve to reach the postseason.

"We have to get focused on in a unique way I think, because last week we leave behind us, last season we leave behind us, and it comes down to championship time," Carroll said Monday.

The second half of the season has been a mess for the Seahawks (6-9), but a win Sunday against St. Louis will give Seattle a division championship banner to hang, a home playoff game and the dubious distinction of being the first sub-.500 division winner in NFL history.

Seattle has lost seven of nine since its 4-2 start, and remains in contention for the NFC West title heading into the final week.

If Seattle can beat the Rams, it would join the 1985 Cleveland Browns and 2008 San Diego Chargers as the only teams in league history with .500 or worse records to reach the postseason as division champs. There have been five teams at 8-8 to make the postseason as wild cards.

The ridiculousness of the situation isn't lost on those involved.

"It's awesome; we should be saying thank you, thank you, thank you, this is just amazing," quarterback Matt Hasselbeck said after Sunday's 38-15 loss at Tampa Bay.

"For us to still have this opportunity as poorly as we have played at times, as poorly as we performed tonight is huge opportunity and one that very, very few teams get."

The Seahawks probably will be without Hasselbeck for the division-deciding showdown after he left Sunday's loss to Tampa Bay with a strain in his lower back/hip/gluteal area. Test results Monday had Carroll optimistic to the point of not ruling Hasselbeck out, but the Seahawks will move forward with Charlie Whitehurst as the starter.

It would be the second career start for Whitehurst and while he did not play well in relief of Hasselbeck on Sunday, Seattle's issues stretch well beyond the quarterback.

The poor showing against Tampa Bay was another game where the Seahawks weren't competitive. Their nine losses are by an average of 21 per game. They have lost by more than 17 points six times.

For the season, Seattle has been outscored by 107 points. It's rare, but not unprecedented for a division champion to be outscored for the year. The 2004 and 2006 NFC West champion Seahawks were both outscored - by two and six points respectively.

But since 1970, the '85 Browns and 1978 Vikings are the only other division champs to be outscored for the season and certainly not at the rate by which Seattle is losing this year.

"We didn't write the way the things are, but at the same time, we're just taking advantage of the situation we're in," Seahawks receiver Ben Obomanu said.

The Seahawks' flaws were exposed again by Tampa Bay. Seattle knew by the time it took the field that the game had no meaning. St. Louis' victory over San Francisco earlier in the day created the situation where win or lose, the Seahawks and Rams would decide the division in the final week.

Carroll was hoping for a little momentum to carry forward and got none.

Seattle's offense stalled without Hasselbeck running the show, gaining just 112 yards in the eight possessions after Whitehurst entered. The run game was especially appalling, with Marshawn Lynch gaining 29 yards on his first carry and just 24 on his next 13. Seattle finished with 90 yards rushing, the eighth time in the Seahawks' nine losses they were held under 100 yards.

But the situation was just as bad on defense where Seattle made Josh Freeman look unstoppable. The young Buccaneers QB threw for five touchdowns, and rookie running back LeGarrette Blount rumbled for career-high 164 yards. Tampa Bay became the sixth team this season to top 400 total yards against the Seahawks defense.

And still, a win over the Rams gives Seattle the division title.

"So this is something that we've aimed for," Carroll said. "It's come in kind of an unusual manner, but the fact that we're there, we're going to go for it and be excited about it and see if we can put together a great game."