"His growing pains mirrored the progress of his team.

A career backup in college and the NFL, Matt Cassel used an impressive, season-long performance with New England in 2008 as replacement for injured Tom Brady to earn leverage for a lucrative, $63 million deal with Kansas City.

But in his first season with the Chiefs last year, Cassel failed to live up to the expectations that come with a huge contract, throwing 16 interceptions as Kansas City struggled to a 4-12 record.

What a difference a year makes. The Chiefs, AFC West doormats for years, are leading the division at 6-4 and are in line to earn their first playoff berth since 2006. And the play of a resilient Cassel has been key to the team's success. The 28-year-old has thrown for 2,074 yards, 18 touchdowns and four interceptions, and has a passer rating of 96.2 heading into today's contest in Seattle.

"Matt works really hard," Kansas City coach Todd Haley said. "He's very hungry to learn and he wants to be a great quarterback, and when you have that combination of characteristics plus a big guy that's athletic that can throw the football and throw it accurately, then you have a chance to have something, and he's making progress daily."

Cassel's careful but productive play is one of the reasons for the Chiefs' league-low seven turnovers this season.

"It's something that's been imprinted and impressed upon us throughout the entire year," Cassel said about limiting turnovers. "We take great pride in it and hopefully that continues."

Of course, Seahawks coach Pete Carroll is familiar with Cassel, who was a sophomore when Carroll became coach at USC.

Cassel lost out in a quarterback competition with Matt Leinart, but ultimately his experience under Carroll with the Trojans paved the way for his successful pro career. The Patriots selected the 6-foot-4, 230 pounder in the seventh round of the 2005 draft.

"(The way) he organized his practices, the mentality that he had, it prepared me for the NFL," Cassel said. "Even when I got to New England, my first few days there it wasn't like I was a wide-eyed rookie. A lot of the drills that we were doing were very similar to what coach (Carroll) had already done with us at USC. So I felt very prepared going in."

Carroll said he's proud to be facing another one of his former pupils in Cassel."