New Orleans Saints defensive coordinator Gregg Williams may be a candidate for one of the head coaching vacancies in the league, but NFL rules will limit his availability. James Varney, of the Times-Picayune, has the story, below.

Defensive coordinator Gregg Williams of the New Orleans Saints looks on prior to the game against the Pittsburgh Steelers at the Louisiana Superdome on October 31, 2010 in New Orleans, Louisiana.

Courtesy--- James Varney/Times-Picayune

With the annual head coaching derby under way, it is no surprise that New Orleans Saints defensive coordinator Gregg Williams has popped up as a candidate. Hall of Fame quarterback John Elway was no sooner installed as a Broncos executive than he announced Williams was one of the candidates Denver hopes to interview for its coaching vacancy.

NFL rules, however, limit Williams' availability. Assistant coaches on staffs involved in the postseason are only permitted to speak with other teams during bye weeks.