Charlie Frye, who was supposed to fight for the second string quarterback job with Oakland, has a mysterious hand injury.
"There's so many things in your hand," said Frye, who has been out nine days with a sore and a braced-up wrist. "I guess they just want to find out some more about what's going on in there, because I can't throw a football."
With Frye's injury a concern, the Raiders signed Colt Brennan as insurance behind Jason Campbell and Kyle Boller.
Frye's Hand Injury Remains Mysterious