[UPDATED with Mark Sanchez Back In:] Matt Leinart May Be the Only NFL Quarterback Out of Orange County (or USC) Starting Sunday

See the update at the end of this post explaining why Mark Sanchez will now start for the Jets.

ORIGINAL POST, DEC. 26, 4:26 P.M.: Who would have seen this coming when the NFL season began? Heading into week 17--the final week of the regular season--the only quarterback out of USC with a chance of starting for his team is the Oakland Raiders' Matt Leinart.

The southpaw has been getting slightly more reps at practice with the starting offense this week, according to Terrelle Pryor, the Raiders' other backup quarterback who, unlike Leinart, has never started an NFL game.

The Raiders are forced to go with a backup against the Chargers in San Diego Sunday because Carson Palmer suffered cracked ribs and a punctured lung in last week's loss to the Carolina Panthers.

Palmer: Done!

Leinart, who was born in Santa Ana and graduated from Mater Dei High School, famously backed up Palmer at USC, where both were Heisman Trophy winners. Palmer came to the Trojans from another Orange County Catholic school, Santa Margarita High School in Rancho Santa Margarita.

Palmer started for years with the Bengals after being Cincinnati's overall top pick in 2003. Leinart previously started for the Houston Texans and before that the Arizona Cardinals, which made him the 10th overall pick in 2006.

Matt Cassel, who attended Chatsworth High School, backed up both Palmer and Leinart during his USC football career. The Kansas City Chief's starter when the season began, Cassel was injured in October of this year. Despite later being cleared by medical staff to play--and new starter Brady Quinn's awful outing against the Indianapolis Colts last weekend--Cassel will be backing up the former Notre Dame star this Sunday against Denver.

Benched

Mark Sanchez, the Long Beach-born pride of Mission Viejo High School and USC who took the New York Jets to the AFC Championship game in his first two seasons, stunk up the field with uneven play this season and has been benched in favor of Greg McElroy, who gets the start this weekend against Buffalo.

Newport Beach's Matt Barkley of USC by way of Mater Dei better hope those picking near the top of April's NFL draft don't pay much heed to Ranking.com's picks of 42 pro quarterbacks, which includes none of his USC predecessors in the top 20.

Cassel is at 25, Palmer at 27, Sanchez at 34 (behind the Jets' third stringer Tim Tebow, No. 30)--and Leinart is not even listed.

UPDATE, DEC. 27, 9:19 A.M.: Because Greg McElroy is being evaluated for a concussion, Mark Sanchez will now start against the Bills, Jets coach Rex Ryan just announced (via NFL.com).

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