Oakland Raiders owner Al Davis has been pushing for Lane Kiffin to resign as his head coach and is considering Dennis Green as a potential replacement, sources close to Kiffin and the team said.

Davis has gone so far to draft a letter of resignation for Kiffin to sign, a source said. Kiffin has refused to do so but has dared Davis to fire him instead.

Kiffin, who was 4-12 in his first season as coach, has two years remaining on his contract at an estimated $2 million per year.

In the letter sent to Kiffin's legal representatives, sources said Davis stated that only he would have control over his staff and full personnel decisions. According to a source close to Kiffin, Davis had promised Kiffin when he hired him that he would have more control over staff and personnel matters than recent Raiders coaches. Kiffin was allowed fire offensive assistants and to name his own staff when he took the job after the 2006 season.

"I'm not going to comment on anything that has transpired in the past three weeks," Kiffin said from Mobile, Ala., where he and the Raiders staff are coaching the North team in the Under Armour Senior Bowl college all-star game.

The Raiders had no immediate comment.

Kiffn and Davis clashed near the conclusion of their postseason evaluation meetings when Kiffin expressed his desire to fire defensive coordinator Rob Ryan, a source said. Ryan himself wanted out to join the New York Jets in a similar capacity, but the Raiders released a statement asking for speculation to cease about the defensive coordinator's future.

Just this week at the Senior Bowl, Kiffin and Ryan both said their relationship was fine and expected to be coaching the team in 2008. However, Davis has not rescinded his request for Kiffin to step down, a source said.

As for Green's candidacy, while team sources said Davis has reached out to the veteran coach, Green said Friday, "I haven't really talked to Al about any coaching job but, really, how many times has my name been mentioned every time something goes on with the Raiders?"

Chris Mortensen covers the NFL for ESPN.

(01-25) 13:59 PST -- Raiders owner Al Davis is locked in a nasty standoff with Lane Kiffin after informing the second-year head coach in a letter received by Kiffin early last week that he no longer has any control of coaching or personnel moves within the organization.

Angry over the team's 4-12 finish and furious at the success achieved this season by former Raiders receiver Randy Moss - Davis believes Kiffin forced 2007's giveaway draft day trade of Moss to New England for a fourth-round draft pick - the powerful owner is now doing all he can to pressure his hand-picked head coach to resign.

Kiffin hasn't been fired, NFL sources confirmed, because Davis does not want to pay him $4 million in salary, the remaining guaranteed balance of the five-year contract (three years plus two club option years) the coach signed when he was hired on Jan. 22, 2007 to replace Art Shell.

Davis reluctantly paid the $2 million remaining on Shell's deal after the Hall of Fame lineman was sacked as head coach on Jan. 4, 2006 following the Raiders' 2-14 finish. It was the second time in 13 years that Davis fired Shell as the Raiders head coach.

To avoid a similar payoff to Kiffin, Davis has gone on the offensive to force Kiffin to leave the Raiders on his own, stripping him of every bit of authority promised to the coach when he was hired on Jan. 22, 2007.

The letter submitted this week to Kiffin amounts to a "you are on notice" declaration, informing the coach that neither he nor his closest ally at the Raiders, director of football development Mark Jackson, will be involved in the scouting, planning or selecting of players in the NFL Draft.

Kiffin also was informed that he will not be involved in the free agent meetings and that he no longer is in charge of his own coaching staff. He may not hire or fire coaches, nor can he order anyone in the Raiders organization to do anything without the permission of the General Partner, that being Davis.

Said an NFL source with direct knowledge of the letter, "Now you know why that place is such a mess right now."

The letter was the first contact between Davis and Kiffin in more than a week, numerous NFL sources confirmed. Davis met individually with each member of the coaching staff on Jan 2. At that time, Kiffin was told that embattled defensive coordinator Rob Ryan would remain on the staff, over the head coach's objections.

Kiffin had spoken openly about his disappointment with the Raiders' defense in 2007, which finished 25th overall in the NFL and 31st against the pass. After the Raiders lost the regular season finale 30-17 to the Chargers, it was widely expected that Ryan and defensive line coach Keith Millard would be fired.

Ryan, it was assumed, would quickly land a job on the staff of his friend Eric Mangini as the Jets defensive coordinator. But Mangini never fired coordinator Bob Sutton, and Davis overruled Kiffin on Ryan's dismissal.

While coaches on Kiffin's staff are expressing concern about their futures in light of Davis' latest power play, Raiders CEO Amy Trask denied that Kiffin has been stripped of his authority over his staff and the roster.

"His authority remains unchanged," Trask said last week when asked if Kiffin had lost any personnel control of the team and whether there was a rift between the owner and coach. "That's simply not true. He has all the authority he had when he was hired. The authority he has or had under his original contract remains unchanged."

By abruptly stripping Kiffin of that authority, the coach and his agent, Gary Uberstine, could have a strong case for a breach-of-contract grievance, a complaint that would be filed with the NFL office. "That would be an easy case to him to win," an NFL source said.

The honeymoon between the Raiders' managing general partner and the NFL's youngest head coach didn't figure to last. The team has not had a winning season since 2002, and Kiffin was determined to change the losing culture. He retooled the roster, asserted himself during the draft and demanded more discipline from a franchise that had long been a players' paradise.

Davis, 78, traditionally has been the final authority on all decisions regarding the Raiders' organization. That he eventually would balk at Kiffin's eagerness to take charge of a flailing franchise should come as no surprise.

Initially, Davis had nothing but lofty praise for Kiffin when he hired the 31-year-old former USC offensive coordinator on Jan. 22 to succeed Art Shell following the Raiders' 2-14 finish in 2006. Kiffin signed a five-year deal (three years plus two club option years) worth $2 million a season.

But Davis' infatuation with Kiffin soured as soon the 2007 NFL Draft, when Kiffin pushed the owner to dump an uncooperative Moss, who happened to be the owner's prized receiver. The Green Bay Packers made overtures to acquire Moss before the draft but Davis was reluctant to close a deal.

On April 29, Davis contends that Kiffin insisted that Moss be dealt to the Patriots in exchange for a fourth-round pick. That selection, the 110th overall, turned out to be cornerback John Bowie, a player who was never active in a game last season.

Davis closely monitored the resurrection of Moss, who went on to catch an NFL-record 23 touchdown passes in the 2007 regular season. During the Raiders trip to Green Bay on Dec. 9, Davis and his entourage were riding the press box elevator to the locker room level. They watched Moss catch a touchdown pass on the flatscreen television monitor inside the elevator.

"Dammit - why couldn't he do that for us?" Davis was overheard saying. Moss caught seven passes for 135 yards and two touchdowns in that Dec. 9 win over the Steelers. In two seasons with the Raiders, Moss caught 11 touchdowns.

(02-28) 20:52 PST -- Hours before the start of the NFL's free-agency signing period, the Raiders locked up run-stuffing defensive end/tackle Tommy Kelly with one of the most eye-opening deals ever for a non-Pro Bowl player: seven years and $50.5 million, with $18.125 million guaranteed.

The contract is the largest ever awarded to a defensive tackle, the position where Kelly, 27, will move to now that Warren Sapp has retired.

Kelly would have been one of the most coveted free agents because of his ability to line up as an end in a 3-4 or as a speedy interior player in a 4-3 scheme. Now he can collect $25.125 million in the first three years of his new contract.