Who is Tyler Palko?

The New England Patriots will find out more about the relative unknown quarterback when they host the Kansas City Chiefs at Gillette Stadium on Monday night.

Palko, 28, will be filling in for injured Matt Cassel, as the Chiefs try to keep pace in the tight AFC West. Palko has bounced around NFL teams, as well as the Canadian Football League, since leaving the University of Pittsburgh, where he was a three-year starter, after the 2006 season.

In front of a nationally televised audience, Palko has been unexpectedly thrust into the spotlight, and could turn out to be the underdog story of the season should he make a strong impression.

To suggest Palko is short on professional experience would be an understatement. Palko has completed nine passes in 13 attempts in his NFL career, so he can expect more plays under center against the Patriots than he's had since college.

The challenge of competing against a top team like the Patriots on their home field is not lost on the first-time starter.

Anyone who has ever accomplished anything great has had to overcome some obstacles,'' said Palko.

The Pennsylvania-native couldn't even crack one of three quarterback jobs in the United Football League, according to famed NFL writer Peter King, who described Palko's emergence as an NFL starter as a heck of a story.

What makes Palko's debut as a starter so interesting is the relationship the story shares with how Cassel emerged as a starting NFL quarterback in his days with the Chiefs' opponent on Monday.

When Pro Bowl quarterback Tom Brady went down in the first quarter of Week One of the 2008 season against the Chiefs, Cassel stepped in and did a solid job filling in for Brady, leading the Patriots to a 11-5 regular season record.

Cassel had a unique route to the NFL. He was the backup to Heisman Trophy winner Carson Palmer and Matt Leinart at USC, and was even used as a tight end with the Trojans. There were times where USC would use a trick play where Cassel would make a reception behind the line of scrimmage and then make a pass up field, but he mostly played a minor role to two more prominent quarterbacks.

When he was drafted in the seventh round by the Patriots in 2005, Cassel was again a backup to a high-profile quarterback. The opportunity to shine in Brady's absence in 2007 has provided the 28-year-old with a regular role as a starter ever since.

While USC coaches chose Palmer and Leinart over Cassel, Palko actually got the starting job at Pittsburgh over future NFL first-round pick, and current Baltimore Ravens' star, Joe Flacco. With Palko as the starter, Flacco decided to transfer to Delaware.

Though Palko was favored over Flacco, his professional career has been as an understudy to bigger names, and he's never been able to showcase his tools.

Not until now.

Monday might be the first and final chance for Palko to prove his skills as a starter. The Chiefs could turn to rookie Ricky Stanzi if Palko struggles. The 24-year-old from Iowa probably would have received the nod over Palko if he was more prepared, and the Chiefs may decide he's worth the risk.

If Palko falters against the Patriots, Chiefs' head coach Todd Haley might also search for an experienced and inactive quarterback to fill in for Sunday's game against the Steelers. The Chiefs are ranked 18th in rushing yards per attempt, so Kansas City may have little choice but to throw the ball.

New England's pass defense is last in average net passing yards per game, so if there is a matchup for a new quarterback to gain confidence, it's against the Patriots.

Palko has some quality targets. Dwayne Bowe is a 2010 Pro Bowl wide receiver, and Steve Breaston averages 14.6 yards per catch. The Chiefs have nine players who have caught five passes or more this season.

Earlier this week, Palko said he received encouraging text messages from Drew Brees and Kurt Warner -- stars who he served as backups to over the past five seasons.

What will be encouraging for the playoff-hopeful Chiefs is if Palko lives up to the Cinderella storyline.