San Ramon Valley High School graduate Sam Keller signed with the Raiders on Wednesday in a move that gives them another viable candidate for the two or three backup spots to projected starting quarterback JaMarcus Russell.

Keller, 6-foot-4 and 235 pounds, went undrafted out of Nebraska earlier this year.

He worked out for the Tampa Bay Buccaneers and the Raiders within the first two weeks after the April 26-27 NFL draft.

"Obviously, there are some people out there who don't think I can play," Keller told the Lincoln Journal Star after he wasn't drafted.

"(Draft) weekend was disappointing. But I guess it's just some more adversity for Sammy."

Keller, 23, signed a three-year contract with the Los Angeles Avengers of the Arena Football League last month but jumped at the opportunity to earn a backup spot with the Raiders.

Russell is the unquestioned starter at this point.

Veterans Andrew Walter and Marques Tuiasosopo are the leading candidates for the Nos. 2 and 3 spots, based on their NFL experience.

It is unclear whether coach Lane Kiffin intends to carry three or four quarterbacks on the opening-day, 53-man roster. Kiffin carried four at times last season.

Keller will compete for a roster spot with Walter, Tuiasosopo and Jeff Otis.

The Raiders waived rookie quarterback Erik Meyer to make room for Keller.

In other news, the man who allegedly robbed and beat Raiders wide receiver Javon Walker

on June 16 in Las Vegas told a judge Wednesday that his fiancée was pressured by police to press domestic violence charges against him in advance of his arrest in the Walker case.

"She was forced by the police, because of the other matter, to go forward with these accusations," Arfat Fadel said as he appeared by videoconference before Las Vegas Justice of the Peace Eugene Martin.

Las Vegas Police spokesman Ramon Denby declined to comment on Fadel's accusation because investigations were continuing in both cases.

He said Fadel had not cooperated with investigators in their attempts to identify a second man suspected of beating Walker.

Fadel faces multiple felonies, including kidnapping, robbery, battery and conspiracy in the incident that left Walker bloodied and unconscious on a Las Vegas street.

Fadel is scheduled to make his initial appearance on those charges today in Las Vegas Justice Court.

The Associated Press contributed to this story. Contact Steve Corkran at scorkran@bayareanewsgroup.com.