Napa, Calif. ? Rich Gannon ended an 18-year NFL career Saturday, retiring from the Oakland Raiders after having missed most of last season with a broken vertebra in his neck.

The 39-year-old quarterback announced his decision – one that had been expected for months – at the team’s wine-country training facility.

“As far as the decision to retire, it was an easy one for me,” Gannon said, sitting alongside team owner Al Davis and coach Norv Turner. “It really was not my decision. I was not able to continue to play physically. That really takes all the guess work out of it for a player like myself, who still feels that he’s got enough left in his tank and enough left in his arm and his legs to play.”

The 2002 NFL MVP already has signed with CBS Sports as an NFL game analyst. Gannon guided the Raiders to the 2003 Super Bowl before spending much of the last two seasons injured.

He injured his neck in the third week last season in a helmet-to-helmet collision with Tampa Bay linebacker Derrick Brooks.

Gannon threw for 28,743 yards and 180 touchdowns in his career with Minnesota, Washington, Kansas City and Oakland. In his MVP season, Gannon passed for 4,689 yards and 26 touchdowns while completing more than 67 percent of his passes. He was selected to four Pro Bowls and was MVP of the all-star game twice.

Texans

Domanick Davis received a new five-year contract and a big raise as a reward for two straight 1,000-yard rushing seasons.

Oakland Raiders quarterback Rich Gannon, shown in this file photo from 2004, announced his retirement on Saturday at the age of 39.

Davis, a fourth-round draft pick in 2003, has 2,200 yards rushing and 21 touchdowns in two seasons. He was in the last year of a three-year contract that paid him $360,000 annually. While financial terms of the new contract were not released, general manager Charlie Casserly said Davis was getting a substantial raise.

Giants and Jets

Giants tight end Jeremy Shockey entered into a fight with two Jets players on the second play of a joint practice between the teams that also featured an argument between Giants coach Tom Coughlin and Jets defensive coordinator Donnie Henderson.

On the second play of a 9-on-7 drill pitting the Giants’ offense against the Jets’ defense, Shockey entered into a tussle with defensive backs Erik Coleman and Oliver Celestin, and soon all three players were throwing wild punches.

Coleman and Celestin pulled the Giants tight end to the ground, and Jets linebacker Jonathan Vilma jumped on top, touching off a melee involving numerous players from both teams. Order was restored after a few minutes. Later in the morning practice session, Coughlin entered into an argument with Henderson after several plays in which the Jets appeared to go beyond the prescribed rules of the practice, which allow defensive players to bump or slow down ball carriers as they go by, without tackling them.

Steelers

Duce Staley’s sore right knee is becoming a concern. Staley, who missed most of the second half of last season because of a sore right hamstring, has sat out all but one full day of training camp contact work because of an aching knee.

After insisting for several days that the injury wasn’t a worry, coach Bill Cowher said Staley would undergo an MRI exam today to make sure there’s nothing wrong.

Ravens

Top draft pick Mark Clayton signed a five-year, $8.2 million contract, ending a five-day holdout.

The wide receiver from Oklahoma was the 22nd overall pick. He will practice with the team for the first time Monday.

Cowboys

Rookie defensive end Marcus Spears rode a stationary bike and could be out about a month after someone rolled on his leg during a drill Friday.

Spears has a sprained knee, a high-ankle sprain and a pulled groin. He was considered a strong candidate to start.

Panthers

Carolina cornerback Ken Lucas pulled his hamstring on the second play of the Panthers’ scrimmage Saturday and sat out the rest of the workout.

Carolina coach John Fox said the team did not know the extent of the injury yet. But Lucas, who signed a $36 million free-agent contract with Carolina during the offseason, said he doubted he would play in next week’s preseason opener against Washington.

Broncos

Broncos quarterback Jake Plummer and defensive lineman Mario Fatafehi each hurt a knee, though Plummer’s injury was not deemed serious and he returned later.

“It’s nothing major, and with a couple of day’s rest it should be OK,” Plummer said.

Shanahan said Fatafehi likely hurt ligaments in his left knee; the early prognosis was that he would miss one to three weeks.

Rams

St. Louis signed defensive tackle John Parella and offensive tackle Matt Willig to one-year contracts. Parella, a 12-year veteran, was with the Raiders the last four seasons after eight years with the Chargers and his rookie year with the Bills.