Source: Rule kept teams from deals

Just as Raiders cornerback Nnamdi Asomugha's contract will allow him to test the free-agent market, Oakland safety Michael Huff's contract is expected to allow him to do the same.

A little-known rule prevented the Raiders from re-signing Huff this past season, as much as they would have liked to, according to an NFL source.

It is a rule that also affected far more players than just Huff.

Any player whose salary escalated at a higher rate than 30 percent from 2009 to 2010, as Huff's and other players' did, was precluded from signing a contract extension with his team, according to an NFL source.

This is not the "30 percent" rule that prevented certain players from signing contract extensions that paid them 30 percent more than their previous deals; this is a separate rule that prevented long-term deals for any player whose salary already escalated more than 30 percent from one year to the next.

The little-known rule prevented high-profile players such as Baltimore Ravens defensive tackle Haloti Ngata, Cincinnati Bengals cornerback Johnathan Joseph, Carolina Panthers running back DeAngelo Williams, Minnesota Vikings linebacker Chad Greenway and Kansas City Chiefs defensive end Tamba Hali from landing the lucrative long-term contracts they desired.

Some discussions for long-term deals for those players occurred, but never could be consummated.

Ngata, Greenway and Hali were ultimately given franchise tenders by their teams. Ngata and Greenway signed their tenders before the NFL locked out its players. The NFLPA is challenging the validity of the franchise tag in its antitrust lawsuit against the league so it is unclear if those franchise tags will be valid once there is a new collective bargaining agreement.

Huff's salary jumped from $945,000 in 2009 to $5.75 million last season, making it impossible for Oakland to sign its 2006 first-round pick to an extension. Oakland placed the first- and third-round, $3.542 million restricted free-agent tender on Huff after last season, but like Asomugha, Huff's contract contained a clause that protected him in a case like this as well.

Huff's contract says that if the Raiders tendered him as a restricted free agent, he must be paid 110 percent more than last year's salary, which would put Huff's salary in 2011 at $6.325 million -- plus a $200,000 Pro Bowl incentive.

Now, whenever football resumes, Huff either will become an unrestricted free agent, able to go to the highest bidder, or Oakland must pay him $6.325 million to retain his services for 2011.

As with Asomugha, Huff's future in Oakland is shaky at best, and the Raiders' secondary likely will be in transition next season. Asomugha and Huff have the same agent, Ben Dogra.

Adam Schefter is ESPN's NFL Insider.