Raiders quarterbacks Matt Leinart and Terrelle Pryor shared reps in practice on Wednesday.
However, coach Dennis Allen did not select a starter for Sunday's game in San Diego.
Both played in last week's loss to Carolina when Carson Palmer went out with cracked ribs and a bruised lung after being hit from behind by Panthers defensive end Greg Hardy.
Allen said Wednesday that Leinart and Pryor split the workload with Oakland's first-team offense during practice, but Pryor later said Leinart took the majority of reps.
Leinart has started just two games since 2007 while Pryor has never started in his two NFL seasons.
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