Pro Bowl cornerback Nnamdi Asomugha's contract voided and he will be allowed to become a free agent without the Oakland Raiders being able to use their franchise tag on him, Raiders senior executive John Herrera confirmed Sunday.

Asomugha's deal included a little-known clause that said his contract would void if he didn't achieve his not-likely-to-be-earned incentives in 2010 -- and he didn't.

His contract also contained a stipulation that if he didn't achieve his incentives, the Raiders would agree not to designate him their franchise or transition player.

"We have to wait on the ramifications of the new CBA to be able to move on," Herrera said.

Asomugha signed a $45.3 million, three-year contract in February

2009 that made him the highest paid defensive back in NFL history.

He was paid $28.5 million in the first two years of the contract.

To achieve his incentives, Asomugha had to play in a greater number of defensive plays in 2010 than he did in 2009, and this season Asomugha played in only 14 games whereas he played in all 16 in 2009.

He also could have achieved his incentives by improving upon on his interceptions, fumble recoveries or sacks this season -- but he didn't have any interceptions, fumble recoveries or sacks this season.

He will be the top defensive player available whenever free agency begins.

Oakland could have many other key free agents this offseason depending on the terms of the new collective bargaining agreement. Pro Bowl defensive tackle Richard Seymour, safety Michael Huff, cornerback Stanford Routt, tight end Zach Miller, left guard Robert Gallery and running back Michael Bush are among the Raiders' other potential free agents.

Asomugha is one of the league's best man-to-man cornerbacks, with most teams choosing not to throw to his side of the field. According to STATS LLC, Asomugha was targeted on just 33 pass attempts this season. He allowed 13 completions for 205 yards and no touchdowns, burnishing his reputation as a shutdown cornerback.

Asomugha was a first-round pick by the Raiders in 2003. After some struggles early in his career as he moved from safety to cornerback, Asomugha has emerged as one of the league's top cornerbacks the past five years. He was recently selected to his third straight Pro Bowl.

But despite the strong play from Asomugha, the Raiders have been unable to put a winning team on the field in his eight years in Oakland. The team lost at least 11 games for an NFL-worst seven straight years in Asomugha's first eight seasons before improving to 8-8 this season.

That improvement did not satisfy owner Al Davis, who announced last week that he would not pick up the option on coach Tom Cable's contract. The Raiders are now searching for their sixth coach since 2003, with offensive coordinator Hue Jackson the leading contender.

Adam Schefter is ESPN's NFL Insider. Information from The Associated Press contributed to this report.