The National Football Post is reporting the Raiders worked out Northwestern quarterback Mike Kafka. Speculation about the quarterback position has been heavy with the Raiders given the struggles last season of JaMarcus Russell, whom the owe $3 million in guaranteed money and $9.45 million should he play this season. Oakland has been linked with Donovan McNabb (since traded to Washington from Philadelphia), Jimmy Clausen (Mel Kiper Jr. has the Raiders taking Clausen at No. 8) and Tim Tebow (NFL.com draft analyst Gil Brandt talked of an Oakland-Tebow visit). Source: Oakland Tribune