MKRob Sports

Matt Cassel, a career backup in college and in the pros, parlayed a great 2008 season into a lucrative franchise tag. Now, he’s locked himself into a deal to be the long-term quarterback of the Kansas City Chiefs.

 Cassel and the Chiefs worked out a six-year deal that will pay him in excess of $10 million a season, according to a source. The contract will keep Cassel with the Chiefs until 2014.

The deal is for $63 million, with $28 million guaranteed, according to a source. He’s going to make $40.5 million in the first three years of his contract.

Cassel was designated as the New England Patriots‘ franchise player in February and signed a one-year deal that paid him $14.561 million. He was then traded to the Chiefs along with linebacker Mike Vrabel for a second-round draft choice.

The Kansas City Star first reported that Cassel had signed with the Chiefs.

Although Wednesday is the deadline for franchise players to get long-term deals, Cassel technically doesn’t apply because he was traded and the team that franchised him no longer holds his rights. Still, the deadline and the start of training camp in two weeks provided both sides with incentive to lock up a long-term relationship.

Cassel replaced an injured Tom Brady in the first week of the 2008 season and threw for 3,693 yards and 21 touchdowns.

Former Patriots GM Scott Pioli, who was responsible for drafting Cassel in the seventh round in 2005, went to the Chiefs during the offseason. One of his first priorities was finding a quarterback and Cassel was his top choice.

Cassel is believed to be the only quarterback in NFL history to start an NFL game without starting a game in college. Cassel was a backup at USC.