ALAMEDA The Raiders worked out veteran quarterbacks David Carr, Trent Edwards and Pat White on Tuesday in an attempt to find an experienced backup to Terrelle Pryor.
The workouts came one day after the Raiders released six-year veteran Matt Flynn.
Coach Dennis Allen said he didn't have a firm plan on how he intended to proceed in terms of replacing Flynn on the 53-man roster.
Pryor, who has started only five games in his three NFL seasons, and undrafted rookie Matt McGloin are the only quarterbacks on the active roster.
Rookie Tyler Wilson, a fourth-round draft pick in April, is on the team's practice squad.
Carr and Edwards have extensive starting experience in the NFL, whereas White has bounced around since he entered the league.
Carr, 34, started 79 games since he joined the league in 2002, but none of those starts came after the 2007 season, when he turned into a backup.
Edwards, who turns 30 later this month, started 33 games from 2007-12.
However, he has appeared in only six games since 2009.
The Raiders have an open spot on their active roster after they waived Flynn and offensive lineman Jack Cornell on Monday and activated wide receiver Andre Holmes from the suspended list.
White, 27, attempted five passes for the Miami Dolphins in 2009 in his only action at quarterback. He was with the Washington Redskins earlier this season.
Raiders in London Oakland will be one of three teams to play one of their eight regular-season home games in London's Wembley Stadium next season, with the opponent and date yet to be determined, the NFL announced.
Also playing home games in London will be the Jacksonville Jaguars and Atlanta Falcons.
"We are excited to embrace this great opportunity to assist in building NFL popularity worldwide," Raiders owner Mark Davis said in a statement released by the league.
Two Raiders players, defensive lineman Jack Crawford and offensive tackle Menelik Watson, are from the United Kingdom. Crawford was born in London and grew up there before moving to the United States when he was in high school. Watson is from Manchester, moving to the United States to play college basketball.
The Raiders have played outside the United States five times since 1990, but never in a regular-season game. The last time the Raiders played outside the United States was on Aug. 27, 2001, when they faced the Dallas Cowboys at Azteca Stadium in Mexico City.